AutoCad Tutorials

Lesson 3-10: Primitive Solids

2011-05-16T05:14:00.000-07:00

For the next few lessons, you should switch to the 3D modeling workspace. Look for the icon in the bottom right of the AutoCAD screen.

What is a Primitive Solid?

A primitive solid is a ‘building block' that you can use to work with in 3D. Rather than extruding or revolving an object, AutoCAD has some basic 3D shape commands at your disposal. From these basic primitives, you can start building your 3D models. In many cases, you get the same result from drawing circles and rectangles and then extruding them, but doing it one command is generally faster. Using these with Boolean operations can be a very effective way of drawing in 3D. There are eight different primitives that you can choose from and are on the Home > Modeling Tool Panel (when in the 3D workspace).

SHAPE	COMMAND	ICON	DESCRIPTION
BOX	BOX		Creates a solid box after you provide 2 opposite corners and a height.
SPHERE	SPHERE		Creates a solid sphere from a center point and radius.
CYLINDER	CYLINDER		Creates a straight cylinder from a center point, radius and height.
CONE	CONE		Creates a tapered cone from a center point, radius and height.
WEDGE	WEDGE		Creates a triangular wedge from 2 opposite points.
TORUS	TORUS		Creates a torus (donut shape) based on center point, radius and tube radius.
PYRAMID	PYRAMID / PYR		Draws a solid object with a polygon (3-32 sides) base that rises to a central point.
POLYSOLID	PSOLID		Draws a solid object with width and height as you would draw a polyline.

You can use primitives to either begin building a model, or it can even be a finished object on its own. Many of these commands are similar to 2D commands, except with an extra co-ordinate in the Z axis. Here is a summary of working with these commands.

BOX

Think of a box as an extruded rectangle. It has width, height and depth. It is created by establishing a starting corner and then establishing a second corner by either picking or giving relative co-ordinates.

Here is an example of this:

Command: box

Specify corner of box or [Center]: 2,3,4

Specify corner or [Cube/Length]: @5,7,10

This draws a box that is 5 units in the X-axis wide, 7 units long in the Y-axis and has a depth of 10 units in the positive Z-axis with one corner located at 2,3,4.

Here is another way of drawing that same box:

Command: BOX

Specify corner of box or [Center]: 2,3,4

Specify corner or [Cube/Length]: @5,7

Specify height: 10

Using this method, you establish the first corner as before, but only enter the X and Y co-ordinates of the opposite corner. AutoCAD will then prompt for the height.

Another way of drawing a box is to establish where the center of the box will be:

Command: BOX

Specify corner of box or [CEnter] < 0,0,0 >: C

Center of box < 0,0,0 >: < ENTER > or < PICK A POINT >

Specify corner or [Cube/Length]: @2,3,4

This draws a box that is 4x6x8 based about the center of 0,0,0.

If you want to draw a perfect cube, you can use this option:

Command: BOX

Specify corner of box or [CEnter]< 0,0,0 >: < pick point >

Specify corner or [Cube/Length]: C

Length: 4

This draws a cube with all sides equal to 4 units based of off a picked point.

The last way of drawing a cube allows you to enter the Length, Width and Height as separate distances, and not based on co-ordinate points.

Command: BOX

Center/< Corner of box > < 0,0,0 >:

Cube/Length/< other corner >: L

Length: 5 < X AXIS >

Width: 4 < Y AXIS >

Height: 6 < Y AXIS >

Of course you can also draw a box by picking two opposite corners with your mouse. This is useful for filling in areas and can be very quick. Make sure to use your Osnaps.

SPHERE

A Sphere is a globe-like shape. It is very similar to drawing a circle in that you pick a center point and then input either the radius (default) or diameter. Both methods draw the same sphere in the following examples:

Command: SPHERE

Specify center point or [3P/2P/Ttr]: < PICK POINT >

Specify radius or [Diameter] <2.3756>: 6 < ENTER >

Command: SPHERE

Specify center point or [3P/2P/Ttr]: < PICK POINT >

Specify radius of sphere or [Diameter]:D

Specify Diameter: 12

Both of the above methods will give you the same result.

You also have the options of selecting 3 Points, 2 Points, or using 2 tangents and radius (TTR).

CYLINDER

A cylinder is just like an extruded circle. Creating one is very similar to creating a circle, except that you are giving depth to it.

These two examples would draw the same cylinder:

Command: CYLINDER

Current wire frame density: ISOLINES=4

Specify center point for base of cylinder or [Elliptical] < 0,0,0 >:< PICK POINT >

Diameter/: 2.5

Center of other end/: 1.2

CONE

Drawing a cone is the same as drawing a cylinder, except that the resulting object tapers smoothly from the bottom to a point at the top.

Command: CONE

Current wire frame density: ISOLINES=4

Specify center point for base of cone or [Elliptical] <0,0,0>:

Specify radius for base of cone or [Diameter]: 4

Specify height of cone or [Apex]: 8

Command: CONE

Current wire frame density: ISOLINES=4

Specify center point for base of cone or [Elliptical] <0,0,0>:

Specify radius for base of cone or [Diameter]: D

Specify diameter for base of cone: 8

Apex/: 8

Another way of drawing a cone is to enter in the center point, the radius (or diameter) and then establish where you want the apex (point of cone) to be. You can either type in co-ordinate points or pick a point with your cursor.

Command: CONE

Current wire frame density: ISOLINES=4

Specify center point for base of cone or [Elliptical] <0,0,0>:

Specify radius for base of cone or [Diameter]: 5

Specify height of cone or [Apex]: A

Specify apex point: @5,5,6

WEDGE

One of the trickier primitives to draw is the wedge. You have to be careful which co-ordinates you input to make the wedge lie in the position you want. If it doesn't turn out just as you hoped for, you can always rotate it.

Here is an example of drawing a wedge:

Command: WEDGE

Specify first corner of wedge or [CEnter]<0,0,0>:

Specify corner or [Cube/Length]: @5,2,4

Once the first corner is established, you can either enter points, or pick a spot. AutoCAD will draw the shape like it would draw a cube except it is slice in half along the length starting at the point above the first corner. There are other options to drawing wedges and see the box examples for these.

TORUS

A torus is a donut-like shape or something resembling an inner tube. When drawing one you have to enter the center point, a radius to the center of the tube and the radius of the tube itself.

Command: TORUS
Current wire frame density: ISOLINES=4
Specify center of torus <0,0,0>:
Specify radius of torus or [Diameter]: 3
Specify radius of tube or [Diameter]:.25

The diagram above shows the resulting diameters from the input above. A center mark indicates the picked center of the torus.

PYRAMID

To draw a pyramid, you need to know the diameter of the base and the height. The diameter can either be inscribed (inside the circle) or circumscribed (outside the circle). You can define the number of edges to from 3 to 32.

Command: PYR
PYRAMID
5 sides Inscribed
Specify center point of base or [Edge/Sides]:
Specify base radius or [Circumscribed] <4.5655>: C

Specify base radius or [Inscribed] <4.5655>: I

Specify base radius or [Circumscribed] <4.5655>: 4

Specify height or [2Point/Axis endpoint/Top radius] <10.0108>: 9

In the above example, I showed how to switch between Inscribed or Circumscribed as the options change depending upon the method selected.

Try creating some pyramids using a variety of methods.

POLYSOLID

This is a new command since AutoCAD 2007. A polysolid allows you to draw a solid object while defining the height and the width. I think this command is aimed at the architects, who will enjoy the ability to quickly draw solid walls.

Command: PSOLID
POLYSOLID Specify start point or [Object/Height/Width/Justify]

Specify height < 96.0000 >: 96
Specify start point or [Object/Height/Width/Justify] < Object >: W
Specify width < 6.0000 >: 6
Specify start point or [Object/Height/Width/Justify] <Object>: J

Enter justification [Left/Center/Right] :L

Specify start point or [Object/Height/Width/Justify] < Object >: < Pick 1st point >

REVIEW
As mentioned in previous lessons, solids are usually the way to go with 3D CAD. Depending upon your chosen field, you may use 3D meshes in Civil Drafting, Isometric in HVAC, solids in mechanical, etc.
I recommend getting used to solids if you are doing any kind of mechanical drafting or architectural drafting if you are using base AutoCAD software. When using solids, you will usually take a shape and extrude it - then use boolean commands and others to edit it. Here is a basic building that was quickly drawn using a variety of primitive solids.

Lesson 3-11: Boolean Operations

2011-05-15T00:43:00.000-07:00

First, to explain the funny name : "It was named after George Boole, who first defined an algebraic system of logic in the mid 19th century."

Working in 3D usually involves the use of solid objects. At times you may need to combine multiple parts into one, or remove sections from a solid. AutoCAD has some commands that make this easy for you. These are the boolean operations as well as some other helpful commands for solids editing.:

COMMAND	INPUT	ICON	DESCRIPTION
UNION (Boolean)	UNION / UNI		Joins two or more solids into creating one based on the total geometry of all.
SUBTRACT (Boolean)	SUBTRACT / SU		Subtracts one or more solids from another creating a solid based on the remaining geometry.
INTERSECT (Boolean)	INTERSECT / IN		Creates a single solid from one more solids based on the intersected geometry.
EXTRUDE FACE	SOLIDEDIT		Allows you to increase the size of a solid by extruding out one of its faces.
SLICE	SLICE		Slices a solid along a cutting plane.
3D ALIGN	3DALIGN		Aligns 2 3D Objects in 3D space.

The boolean commands work only on solids or regions. They are easy to work with IF you follow the command line prompts. Here is an example of each.

Start these exercises by drawing a box 5W X 7L X 3H and a cylinder 3 units in diameter so that the center of the circle is on the midpoint of the block.

UNION

Below left, there is a box and a cylinder. These are two separate objects. If you want to combine them into one object, you have to use the union command.

The UNION command combines one or more solid objects into one object.

Here are the command line prompts and the resulting object:

Command: UNION < ENTER >
Select objects: < SELECT THE BLOCK > 1 found
Select objects: < SELECT THE CYLINDER > 1 found
Select objects: < ENTER >

NOTE: The object that you select first will determine the properties of the unioned object when it is created.

SUBTRACT

The subtract command is used to cut away, or remove the volume of one object from another. It is important to check the command line when using this command. Remember that AutoCAD always asks for the object that you are subtracting FROM first, then it asks for the objects to subtract. Here is an example:

The SUBTRACT command removes the volume of one or more solid objects from an object.

Command: SUBTRACT
Select solids and regions to subtract from...
Select objects: < SELECT THE BLOCK > 1 found < ENTER >
Select objects: Select solids and regions to subtract...
Select objects: < SELECT THE CYLINDER > 1 found < ENTER >
Select objects: < ENTER >

You can also Subtract any number of solids from a number of solids. If you do this, the solids that you subtracted from will become ONE object - even if they are not touching. Be careful with this (although you can always slice the object if you need to).

INTERSECT

This command creates a new solid from the intersecting volume of two or more solids or regions. AutoCAD will find where the two objects have an volume of interference and retain that area and discard the rest. Here is an example of this command shown below:

The INTERSECT command combines the volume of one or more solid objects at the areas of interference to create one solid object.

Command:INTERSECT
Select objects: < SELECT THE BLOCK > 1 found
Select objects: < SELECT THE CYLINDER > 1 found
Select objects: < ENTER >

You can intersect solids that are not touching - they will become one object.

Try these 3 boolean commands with various 3D solid objects to get familiar with them. Draw the block in Lesson 3-2. Draw the outline of the block, extrude it - then draw the circle and extrude it. Then subtract the circle from the block.

These commands will allow you do a lot of 3D work, using only the extrude and these boolean commands. Of course, there are some other ways to edit 3D solids.

SLICE

This command does exactly what the name implies. You can slice a 3D solid just like you were using a knife.

Start with the basic block and cylinder shape you used in the examples above.

The INTERSECT command combines the volume of one or more solid objects at the areas of interference to create one solid object.

Command: SLICE
Select objects: 1 found
Select objects: Specify first point on slicing plane by
[Object/Zaxis/View/XY/YZ/ZX/3points] <3points >: < PICK POINT 1>
Specify second point on plane: < PICK POINT 2 >
Specify third point on plane: < PICK POINT 3 >
Specify a point on desired side of the plane or [keep Both sides]: < Pick on the side towards the cylinder >

This is a very useful command - think of it as a trim in 3D. Make sure you have your Osnaps on for this command and that you pick the correct points. In a complex 3D drawing, this can be tough to see. Undo this slice and try picking 3 other points. See if the results match what you thought they would do.

This is a very useful command - think of it as a trim in 3D. Make sure you have your Osnaps on for this command and that you pick the correct points. In a complex 3D drawing, this can be tough to see. Undo this slice and try picking 3 other points. See if the results match what you thought they would do.

EXTRUDE FACE

Just as there is a "trim"-like command in 3D - there is also a "stretch". This is a new command in recent versions. More Info

I usually start this command by clicking on the Ribbon item Home > Solids Editing > Extrude Faces.

The command is quite easy to use, but you need to be careful on which face you select.

Try to extend one edge of the block by 1 inch. Start the command and pick the face on the side (on the bottom line). You'll notice that the bottom face highlights as well. Next type R and pick the bottom face to remove it. Then follow the command line to finish the command.

Command: _solidedit
Solids editing automatic checking: SOLIDCHECK=1
Enter a solids editing option [Face/Edge/Body/Undo/eXit] < eXit>: F
Enter a face editing option
[Extrude/Move/Rotate/Offset/Taper/Delete/Copy/coLor/Undo/eXit] < eXit>: E
Select faces or [Undo/Remove]: < PICK BOTTOM LINE OF SIDE FACE> 2 faces found.
Select faces or [Undo/Remove/ALL]: R
Remove faces or [Undo/Add/ALL]: < PICK AN EDGE ON THE BOTTOM FACE> 2 faces found, 1 removed.
Remove faces or [Undo/Add/ALL]: < ENTER >
Specify height of extrusion or [Path]: 1 < ENTER >
Specify angle of taper for extrusion <0>: < ENTER >
Solid validation started.
Solid validation completed.
Enter a face editing option
[Extrude/Move/Rotate/Offset/Taper/Delete/Copy/coLor/Undo/eXit] < eXit>:< ENTER >

You should end up with this:

Another way of editing faces in AutoCAD 2007 and newer is to use grips to extrude the faces, just like you would on a 2D object. Here is an image below that shows some of the grips available.This option is only available on the basic shapes shown in lesson 3-10.

3D ALIGN

Sometimes, you may find it faster or easier to draw something separately and then move and align it into place. The command to use this in 3D is (funnily enough) 3DALIGN.

This is a simple example, but will show you the method.

Draw a box that is 5 x 5 x 6 tall. Next draw a cylinder that is 3 in diameter and 1 tall. It should look like this:

The goal will be to align the cylinder on the front face of the box where the dotted line is.

Turn on your quadrant Osnaps. Start the 3DALIGN command. You will first be asked to select the objects - select the cylinder and press enter.

Now you will be asked to select the 3 points as indicated below: the center and 2 quadrants. Now the cylinder will be "stuck" to your cursor as AutoCAD asks where it needs to go.

Line the cylinder up with the box by using object tracking to locate the center of the face on the box first. Then pick on the midpoints to line up the cylinder to the box. After you pick the 3rd point, the cylinder should move into place and end the command.

Here's a view of the points that were picked incase you had trouble.

The finished 'alignment job' should look like this after using the hide command.

Review:

After learning how to draw some basic 3D solids, you can see that using equally basic editing commands you can have a lot of options. Before advancing, review these commands by drawing simple 3D shapes and editing them.

With the commands explained on these pages, you will be able draw most of the shapes you will need in 3D. There are other options, but get very familiar with these 3D editing options before moving on. The drawings done in the sample drawing section were done almost exclusively with the commands taught in Lessons 3-7 to 3-11. Your approach will make the project either easy or difficult. Think of the various ways to draw an object before starting. You could save days with some forethought.

Lesson 3-12: Changing from The WCS To the UCS

2011-05-08T08:10:00.000-07:00

Topics covered in this Lesson:
Setting and Using the UCS | Dynamic UCS

When working in 3D, it sometimes necessary to change the plane that you are drawing on. For example, if you need to add some detail to the side of a wall, you would want to draw on that plane. It's like taking a sheet of paper up off the floor (WCS) and taping it onto the wall (UCS).

The WCS is the World Co-ordinate System. This is the way that the standard X,Y and Z axis are directed when you begin a new drawing (X to the right, Y pointing up and Z pointing towards you). The UCS is the User Co-ordinate System. This is a ‘redirection' of the WCS based on parameters set by the AutoCAD user.
There are several ways of doing this, and we'll look at an example here.

This is a simple shape drawn on the WCS with one corner located at 0,0,0.

Here is the same object shown a new UCS based on the side of the object, so that you are enabled to draw on the side of the building - maybe to put a door in? Note the direction that the X and Y axes are now pointing.

Notice that the positive X Axis is now pointing along side of the structure.

Here's how it was changed: You first choose the 3 point option by typing 3 at the prompt. Next you have to pick three points to define the plane. The first point is the new origin. The second point is where you want the positive X-axis to be positioned. The last point is for the positive Y-Axis.

Command: UCS
Current ucs name: *NO NAME*
Enter an option [New/Move/orthoGraphic/Prev/Restore/Save/Del/Apply/?/World]
: 3
Specify new origin point <0,0,0>: < P1 >
Specify point on positive portion of X-axis <1.0000,7.0000,0.0000>: < P2 >
Specify point on positive-Y portion of the UCS XY plane
<1.0000,7.0000,0.0000>: < P3 >

This is the ‘3-Point' option of the UCS Command. It is one of the most useful, because you control exactly where the new drawing plane will be. You must also be extremely careful when picking the 3 points, or your plane can be shifted and cause some major problems. I would recommend using this method for most of your UCS work - or at least get very comfortable with it before moving on to other methods.

NOTE: Pressing enter immediately after entering the UCS command accepts the default of returning to the WCS.

Here are the other options of the UCS command.

ORIGIN:

Command: UCS
Origin/ZAxis/3point/OBject/View/X/Y/Z/Prev/Restore/Save/Del/?/< World >: O
Origin point <0,0,0>: < PICK A POINT >

This option moves the UCS based on a newly picked origin point. It does not shift the drawing plane at all as you only pick one point.

Z-AXIS:

Command: UCS

Origin/ZAxis/3point/OBject/View/X/Y/Z/Prev/Restore/Save/Del/?/: ZA

Origin point <0,0,0>: < PICK A POINT >
Point on positive portion of Z-axis <-8.0000,0.0000,1.0000>: < PICK A POINT >

This choice allows you to pick two points. First you pick the new origin, then you pick a point for the positive Z-Axis. Make sure you type ZA to choose this option.

OBJECT:

Command: UCS
Origin/ZAxis/3point/OBject/View/X/Y/Z/Prev/Restore/Save/Del/?/: OB
Select object to align UCS: < SELECT AN OBJECT >

Using this method, you have to pick on a 2D object that is lying on a particular drawing plane. This gets tricky, as you have to be aware how your positive X and Y axes end up.

VIEW:

Command: UCS
Origin/ZAxis/3point/OBject/View/X/Y/Z/Prev/Restore/Save/Del/?/: V

By choosing the view option, AutoCAD will automatically reset the UCS to be aligned with your current view, keeping the origin where it was previously located.

X / Y / Z:

Command: UCS
Origin/ZAxis/3point/OBject/View/X/Y/Z/Prev/Restore/Save/Del/?/: X
Rotation angle about X axis <0>: -90

By selecting either the X, Y or Z options, you need to first pick a point along the axis you have chosen, then provide a rotation angle based on the right hand rule mentioned earlier. This example shows how you would rotate the UCS -90 around the positive X axis.

PREVIOUS:

Command: UCS
Origin/ZAxis/3point/OBject/View/X/Y/Z/Prev/Restore/Save/Del/?/< World >: P

This option returns you to the last setting you had for the UCS. You'll use this one a lot in 3D. You might need to change your UCS to draw one object, then go back to what you had it set at before.

Restore/Save/Del/?/

The next options are used in conjunction with each other. You have the option of saving a particular UCS with a name. You can then restore that named UCS or delete if you no longer will be using it. Here are examples of these options:

Command:UCS
Origin/ZAxis/3point/OBject/View/X/Y/Z/Prev/Restore/Save/Del/?/: S
?/Desired UCS name: VIEW1
Command:UCS
Origin/ZAxis/3point/OBject/View/X/Y/Z/Prev/Restore/Save/Del/?/: R
?/Name of UCS to restore: VIEW1
Command: UCS
Origin/ZAxis/3point/OBject/View/X/Y/Z/Prev/Restore/Save/Del/?/: ?
UCS name(s) to list <*>:
Current UCS: VIEW1
Saved coordinate systems:
VIEW1
Origin = <0.0000,0.0000,0.0000>, X Axis = <1.0000,0.0000,0.0000>
Y Axis = <0.0000,1.0000,0.0000>, Z Axis = <0.0000,0.0000,1.0000>
Origin/ZAxis/3point/OBject/View/X/Y/Z/Prev/Restore/Save/Del/?/: D
UCS name(s) to delete : VIEW1
Deleted 1 UCS name.

This was a series where a view named VIEW1 was saved, restored, listed, and then deleted.

DYNAMIC UCS

Another option to try is using Dynamic UCS, but I don't recommend this technique for new users. Here it is anyway. Down on the status bar, you have an icon that turns this setting on or off.

With Dynamic UCS turned on, you can easily draw on any surface you want. If you have a drawing like the basic building shown at the top of the page, you can draw a rectangle or box on the roof without manually setting a new UCS. The key is to look and see which face is highlighted as you move your cursor on the screen.

In the images below, you can see how this works. The left side shows the 'roof' face is highlighted and the cursor has changed to reflect the new UCS. The right shows how this looks when the right side face is active. Not the change in the colored cursor while the UCS Icon remains the same.

Other notes about the UCS:

Be careful when choosing a UCS. Look to the UCS icon and see that it is aligned the way you want it to be. Look for a clean vertical lines if it should be aligned along a vertical plane. Most of the time I will use the 3 Point UCS option and then Previous to return and then back to a different 3 point option and so on. 3 Point gives me a lot of versatility without having to think about it too much (and concentrate on how I'm going to draw the project.

Always be aware of where your UCS is located. Make sure that positive X is where you expect it to be.

Lesson 3-13: Mapping Materials

2011-05-08T07:55:00.000-07:00

Topics covered in this Lesson:
Mapping materials on Objects

Whenever you are attaching materials to an object in AutoCAD, you are effectively ‘stretching' the image of the material around the object. For many objects, this can be acceptable. For a lot of others, though, you may want to adjust how the material is displayed on the object. This process is called mapping. The commands in this lesson replace the SETUV commands used in previous versions of AutoCAD.

Here is an example of the same object with the same material, but with the mapping of the material adjusted on the right-side object.

By default, AutoCAD will apply the material as it sees fit. In this example above, the scale of the material is too small. To properly render the block, mapping is used to adjust and fine tune the material so that it looks the way you want it to appear. With a little knowledge of this command, you can make your renderings more realistic.

Here are the commands needed for mapping your materials:

COMMAND OR INPUT	ICON	LOCATION	DESCRIPTION
MATERIALMAP / SETUV		Render > Materials > Material Mapping	Enter this on the command line to select mapping options via keyboard or icons.
Planar Mapping		Render > Materials > Material Mapping > Planar	Maps individual faces of an object.
Box Mapping		Render > Materials > Material Mapping > Box	Maps any solid object with controls for width, depth and height as well as rotation on all sides.
Sphere Mapping		Render > Materials > Material Mapping > Spherical	Allows you to map any solid object, but uses rotation only.
Cylinder mapping		Render > Materials > Material Mapping > Cylindrical	Maps a solid object with height and rotation only.

Start by selecting the Ribbon Location Render > Materials > Material Mapping (or CTRL+3) and you will see a large palette appear that includes the default material library.

The palette you have just opened contains all the default palettes in AutoCAD. You may or may not see the one you need when you open them up this way.

The palette you want for this exercise is the one called "Masonry - Materials Sample".

If you don't see it, click in the area shown by the red box in the image to the left. This will display a list of all palettes available. Select the one needed for this exercise and it should then look like the one shown on the left.

Once you see the correct palette, click the icon on the top for the Masonry.Unit Masonry.Brick.Modular.Common.

This action will add it to your materials palette (which you will see in the next steps).

Start by drawing a box that is 120x120x240 high and do a Zoom > Extents. Set your visual style to Realistic (Render > Visual Styles > Realistic). Switch to the SW ISO view.

As shown in lesson 3-9 apply the material called "Masonry.Unit Masonry.Brick.Modular.Common." to the box. Depending upon your settings it may look something like this in a default view.

In this view, you can see the bricks, but we want to make them bigger - this is done via mapping.

We'll start with the BOX MAPPING icon and then select the box and press enter.

You should now see some new grips on your object (this are different from the grips that allow you to adjust the size of an object.

The above image shows the added options when the rotate option < R > is selected on the command line.

With the grips active, you will need to make the map larger by selecting the mapping grips one at time to make the material bounding box (in yellow) larger. Once you have finished moving a grip, click in the drawing space to release it. Note that there is one on the top as well (for height) as well as the four at the bottom. When you are happy with the look, press enter to end the command. Your new and improved box could look something like this:

As you can see, the one on the right looks better than the default on the left.

Now start the Box Mapping option again, and type in R < ENTER > to invoke the Rotate option. You should now see the circular grips as shown two images above. To rotate the map, move your mouse over one of the circles and it will change color. Click and you will be able to rotate the material around the axis you chose.

From these simple options, you can control the look of any material on any object. Ultimately, the look of your final rendering is the choice of you - the designer.

The image below shows the options below for the cylindrical and spherical mapping commands:

The left image shows the options available with the spherical mapping command. Note that it is limited to Rotation and Moving.

The right image shows the options of the cylindrical mapping command. It is limited to rotation and height adjustment.

Try the two mapping methods shown above on a sphere and cylinder. Then try using the Box Mapping command on those objects. You may find that in common usage, the Box Mapping method will provide you with the most versatile options to achieve the look you want.

PLANAR MAPPING

The other option not discussed yet is the PLANAR MAPPING command. It works a little differently than the others in that adjusts the material on one face only instead of the whole object.

Draw a cube 120x120x120. Apply a material to it that has some contrast to it so you can see the results clearly.

Start the Planar Mapping Command using this icon:

Instead of just selecting an object, press the Control Key as you click the box and you will see that only one face is highlighted. Click on the face that you want to map. From there, you will see that you have the same resize and rotate grips available to you, but will only affect the one face you selected.

For practice, try mapping several different materials onto various objects of different sizes. You will need to get very familiar with this concept to produce decent renderings.

Lessson 3-14: Creating New Materials

2011-05-08T01:18:00.000-07:00

Topics covered in this Lesson:
Creating your own custom materials

Once you start working with AutoCAD's default materials, you'll soon realize that you don't really have a large selection. What if you need a white stucco material for a wall? Or grass for the lawn, or brushed aluminum, or... well, you get the picture. What you need to do is create your own materials.

The first step is to locate an image that represents the material you want in your drawing. There are a number of sources available on the internet. Check out the links page for some. Below are 3 samples you can try for this lesson.

Metal Sample	Brick Sample	Wood Sample

Pick on any of the images above and when the new window opens, right click on the large image and select "Save image as..." and save it in a folder where you can find it easily.

Now start the MATERIALS command to open the Materials Palette.

At first glance, this will look very different if you are used to previous versions of AutoCAD. If you have used 3D Studio MAX, then it may look familiar.

Palettes are used in AutoCAD in much the same way as dialog boxes. A big difference is that they can be left on the screen while you are drawing. You can expand or collapse a palette by clicking the < or > buttons on the bottom left. Close it by clicking the X on the top left corner.

In the top section of the palette is the materials used in the drawing shown as balls in default view. Below are buttons you will be using to work with the material, and at the bottom is a section for editing the material.

I will take you through the simple process of creating a material from an image file and applying it to an an object in your drawing. Then you will learn how to modify the material.

The small red box shows where some icons are that you will be using this tutorial. The larger red box shows where the controls are to modify your material.

Other lessons will give you more information on mapping the material to an object.

To create a new material from one of the images from above (or another texture) open the materials palette and click New Material button. This will open a dialog for naming.

Give it a good name and description (start with good habits) and press OK. Now you are back in the Materials Palette.

Editing Basic Materials

Using the sliders in the Material Editor - Global section, try some new settings on your new material. Here are the setting I made for the material shown below.

Although the example above is very basic, it shows how you can quickly create some materials for a fast rendering. Keep this in mind when you are just starting your rendering process or when you don't have any advanced materials to work with.

Editing Custom Materials

Create another new material like you did above. Instead of editing the material, this time you will use on of the images you saved (from above) to create a more realistic material.

Click on the Select button in the Diffuse map section:

You should notice a new ball in the top section that has the material mapped to it. The clarity of the material will depend on it's contrast in the image and the size of the ball in the top section.

Now is the east part. Draw a solid object of some kind. Highlight your new material by clicking on the ball. Next click the Apply Material to Object button Add Material Button. Finally, select the object.

If everything looks right, great. If not, you may have to use the mapping tools you learned in Lesson 3-13 to adjust the material to your liking.

Another option to get the materials set in scale to the object is to use the "Scale to Object" setting in the Materials Palette. This is found after you have created a new material next to the Select... button which will open up the Adjust Bitmap dialog (formally found in the SETUV command).

This will help get the scale close to what you want it to be, of course this depends on the size of your original image file (as a rule, larger files are better as you can scale them down and retain clarity) and the size of your object. This dialog box also allows for more settings, but each will apply to your own specific needs and image files. Try different settings and check the results. There are an infinite number of possibilities - so explore - go crazy with it - have fun.

To make the material transparent or translucent, move the opacity slider on the Materials Palette to about 50 - making the material 50% transparent. You can adjust other options as shown in this dialog box.

This is just an introduction to the world of creating new materials. If you have a photo editing program like Photoshop, Gimpshop (it's free) or another, you will be able to adjust the image files to fit your needs.

For practice, here is good way to get graphics into your renderings. Draw an octagon (POLYGON command) and turn it into a REGION. Then create a new material using this image of a stop sign and apply it to the region. You will most likely have to adjust map settings to make it look good (or use the scale to object option shown above). For even more fun, add a wooden pole to it and use 3DROTATE to make it stand up properly.

For more practice, try downloading some images or using ones that you already have and apply them to objects. Use the mapping tools to adjust them.

Lessson 3-15: Extra Projects And A Tutorial

2011-05-08T01:09:00.000-07:00

Topics covered in this Lesson:
Putting the concepts into practice

There is only one way to get better at AutoCAD and that is to practice. In 3D, you not only need to know the commands, but also how best to use them. As you start drawing in 3D, you may start looking at everyday objects and think about how they would be drawn. Look at the sample drawing page and think about how they were done - using only the commands shown in this level.

EXTRA PROJECT - A

If you have finished the previous exercises and would like more practice, try this:

Sketch out a simple coffee table on paper. Add the basic dimensions. Draw this in AutoCAD using any 3-D method. Once you've done this, draw another lamp and place it on the table. Use rotate3d if you need to turn it right-side up. Find a good view to display what you have drawn. Add materials.

EXTRA PROJECT - B

Take your file from Lesson 3-7 that gave you a solid model and use the fillet and chamfer commands to add some smoother corners to your chair.

EXTRA PROJECT - C

Draw the object that you draw in the isometric lesson in 3-D using extruded regions. You will have to first create the outline, then the circle. Turn both objects into regions. Subtract the circle from the outline to have one remaining region. Extrude this to get your solid object.

TUTORIAL - CREATING A 3D OBJECT FROM A 2D PROFILE

For this tutorial, you should be familiar with these commands: region, extrude, union, subtract.

This tutorial shows you a method for quickly turning 2D shapes into 3D objects. One of biggest problems with 2D objects is that they are not always drawn properly. This is something that should have been addressed when it was first drawn, but here is a way of working around it.

First lets start with a basic shape (remember the array command). This is the profile for a gasket. It is drawn in 2D with lines, arc and circles.

Let's hope it was well drawn, meaning no overlapping lines, gaps, etc. Copy the objects over to the side for the next section.

Here is how you turn it into a 3D object easily. Start the REGION command. Draw a crossing window around the whole area and press enter. Once you have your regions created, you can extrude them. Start the EXTRUDE command and select all objects. Press enter and enter your extrusion height and taper angle. When these are extruded, begin your SUBTRACT command and first select the larger object first (to be subtracted from), press enter then select all the other objects and press enter. When you change to your SW Isometric view, type in HIDE (enter) and you should see the object as shown below.

Remember that you can always work in your SW Isometric view to see the progress of your 3D work.

There is one problem when using the REGION command. If have two lines that are overlapping, AutoCAD can not make a region out of the objects. You could search until find the offending line, but there is an easier way. Here's this approach:

Now look at the copy of the shape that you made you earlier. Instead of using the region command, use the BPOLY command. This command works similar to the HATCH command in that it finds the boundaries for you. Start the command and you will see this dialog box come up:

Accept the defaults and press on the Pick Points button. In your drawing screen, pick an internal point as if you were hatching it and then press enter.

Now start your EXTRUDE command and select the last (L) object created and extrude it. Now begin the SUBTRACT command and select the outside object, (press enter) then use a crossing box to select everything else and press enter. Use the HIDE command to ensure that everything is as it should be.

Lesson 3-16: Put It All Together - Model A Building

2011-05-07T22:24:00.000-07:00

Topics covered in this Lesson:
Creating a Building in 3D

If you have completed the previous lessons in this level, you now have the tools to create a large variety of objects in 3D. This lesson is designed to show how to create simple building in 3D from start to finish. The same process can be used to build more complex buildings as well.

Below is an image of the final building that is explained in this lesson.

Start by setting your units to architectural (DDUNITS). Remember to create new layers for each type of objects you will draw (windows, doors, walls, roof, etc). Also use the "Render > Visual Styles > Realistic" option when adding materials.

Now draw the bases of the walls using the dimensions are shown below. You don't need to dimension it. Optionally, you can use the (new in AutoCAD 2007) POLYSOLID command.

Now you will create regions out of all your wall lines.

Command: REG REGION
Select objects: < SELECT ALL THE LINES > Specify opposite corner: 7 found
Select objects: < ENTER >
3 loops extracted.
3 Regions created.

You should now have 3 regions. If you don't then it usually means the your lines don't meet.

Next you are going to EXTRUDE the walls 9' high.

Command: EXT EXTRUDE
Current wire frame density: ISOLINES=4
Select objects: < SELECT THE 3 REGIONS > Specify opposite corner: 3 found
Select objects:
Specify height of extrusion or [Path]: 9'
Specify angle of taper for extrusion <0>: < ENTER >
It should appear that nothing has happened. You will need to go to the SW Isometric view to see how the wall were extruded. Do this and then use the HIDE Command. Something doesn't look right. What you will need to do is Subtract the 2 smaller regions from the larger region. You should see this result after the Subtract and Hide commands.

Now it's starting to look like something. Your walls are almost complete.

Next you will add a door or two. The first door, on the outside will be on the bottom left wall. Start by drawing a rectangle from the middle of the outside wall and the other corner @6,36 - this will create the opening. Your rectangle should look like this:

Now you want to EXTRUDE the rectangle up 6'8" and SUBTRACT it from the wall.

Create a door layer (or make it active if you already have one) and draw a rectangle in the door opening that is 3"x 3' - put it in the middle of the door opening. Extrude it 6'8".

Now create a second door (and opening) on the inside wall parallel to the outside wall that is 32" wide. After you do that, the drawing should look like this from the SW Isometric view:

If you haven't saved your drawing yet, now would be a good time.

Now you're going to add some windows. This will be done using a similar process as the door. You will create openings, then add the window.

Create 2 rectangles in the position shown below.

EXTRUDE the window 36 inches. Them move them up 3'8" in the Z axis. Remember your relative co-ordinates from Lesson 1-1?

Command: M
MOVE
Select objects: 1 found
Select objects: 1 found, 2 total
Select objects: Specify base point or displacement: < PICK ANYWHERE ON SCREEN >
Specify second point of
displacement or : @0,0,3'8

Now mirror the bottom left box to the opposite wall (Note: It will be easier if you revert to the top view for the mirror command)and the upper box to the inside wall so you have the 4 boxes looking like this :

Next, subtract the four window openings from the walls. After switching to SW Isometric view and using the hide command, your drawing should look like this:

Now the window panes have to go in. Since this is a simple drawing, you just be putting in a plane of glass to represent the window.

Create a new layer for windows. The easiest way to do this is just like you created the doors. Make the window 1" deep. Once again, start with the rectangle at the base of the window opening, extrude it the height of the window opening and move it into the centre.

Once you have one window made, copy it to the other openings. Save your drawing and then type in SHADE and choose the G option. Your building should look like this:

Wow - now you're getting there. Next you will add to the walls to make them the right pitch for the roof.

First you will have to change your UCS. Start he UCS command and choose the 3Point option by typing 3 < ENTER >. When prompted (watch the command line) select the points shown below:

After you pick the third point, the cursor should turn on its side. Now you can draw on the side of the building. In this case, you will be drawing a triangular shape to represent the rest of the wall up to the roof.

Draw a LINE from the middle of the top outside of the wall up 6'. Then draw a POLYLINE from one corner, to the next, to the top of the line and use the C option to close the polyline.

Finally EXTRUDE the triangle -6" and then COPY the extruded object to the other side of the building. Erase the vertical line you drew. You should have something like this now:

To finish the wall, perform a UNION (Lesson 3-11) between the triangular sections and the bottom wall.

You're almost done now. You will need to draw the roof to complete the drawing.

First you will need to change your UCS to align it with the slant of the roof. Use the points shown below - and be careful which endpoints you select.

Now draw a RECTANGLE from the top left corner of the triangular shape to the bottom of the opposite corner of the other triangular shape. It should like the magenta rectangle below:

New EXTRUDE the rectangle 6". Then copy 12" down in the Y Axis and then copy it 12" up in the Y Axis - when you have the 3 sections UNION them into one object.

Change back to the WCS (UCS < ENTER >< ENTER > ) and mirror the roof object to the other side. Check that it looks correct by viewing the model from the left and from the front.

The last thing to do is trim the excess pieces off the top of the roof where the two slabs intersect. This will be done using the SLICE command (Lesson 3-11).

Go to the SW Isometric view.

Start the SLICE command and select the roof section towards the back. Then when you are asked to pick three points on the slicing plane, select any three points on the top of the roof section at the front.

Switch to the NW Isometric view and slice other roof section in the same manner. Check to see that your roof looks correct, and if it is, union the two roof objects now.

Go to the WCS and copy the roof 12" in the Positive X Axis and 12 " in the Negative X Axis and then union all 3 roof objects. Your building should now look like the one below:

Your building is complete. To add a lawn , draw a very large rectangle around the house at the same Z level as the bottom of the house. Then turn it into a region so that materials can be added later.

Save the drawing, then if you like, add materials and render the final image. In the image at the top of the lesson, the door is detailed material. More detailed instructions for rendering will be found in Lesson 3-17.

Here are the materials used for the rendering at the top of the page. You can download them and add them to your Textures folder. The door texture would be used like the stop sign you may have rendered in lesson 3-14.

door.jpg | grey_roof_slate.jpg | grass.jpg | stucco_white.jpg

You can also try to add more detail to the building if you like. But now you can see that using a few commands (in this case about 12), you can draw decent looking models.

Lesson 3-17: Introduction To Rendering And Lighting

2011-05-07T09:17:00.000-07:00

Topics covered in this Lesson:
Basic Lighting and Rendering

If you have successfully worked your way through this level, you should be able to create some decent looking models in AutoCAD. The next step is learning to render them. This lesson will include a look at the new lighting and rendering options in AutoCAD 2007.

Looking at the image below, from Lesson 3-16, you'll notice that it has a background of clouds, shadows and looks (if you squint) real. You should already know how to create the model, view in a perspective view, add materials, map them and look at them in the viewport. The next step is to create lighting, add a background and render the scene out to a file.

This lesson will use the house model as an example. If you didn't draw it (yes, you should have) here is file that you can download as well as the textures used.

FILE                                FILENAME
Building drawing file         building.dwg
Roof material                  grey_roof_slate.jpg

Grass material         grass.jpg
Wall material           stucco_white.jpg
Door material         door.jpg
Sky background             sky.jpg

Here's the drawing 'as-is' with the Visual Style set to Realistic - with materials added, but not mapped.

Now with the materials mapped, it's starting to look more realistic:

Next step is to add a background to the scene. To do this, you'll have to create a new view. Set up a perspective view similar to what's shown above (see Lesson 3-4) and name it using the VIEW command. The comes witha ready made perspective view (PERS). Click on this. Under the General settings, you will see one for Background. Select this and choose Image. This overrides other background settings used in other views.

Find the sky.jpg and select it in the next dialog, then select the "Adjust Image " button.

This will give you the next dialog that allows to scale the image for the background. This is similar to setting your Windows desktop background. Choose Stretch in this example.

Press OK and OK and Apply and OK to get back to the drawing screen. If all went well, then it should look something like this:

Ok, not the best background, but you now know the concept.

So now you have the model, the materials, the mapping and the background. All that is left is some light and shadows. There are three types of lights in AutoCAD: Point, Spotlight and Distance. I'll show how each one is created and adjusted.

One form of a distance light is the Sun (most distance of all light).

To do this, type in SUNPROPERTIES or (menu: Render > Sun and Location). It will give you this palette:

This palette allows you to control the Sun. Yes, it sounds very powerful, and it is. First you must turn on the Sun, if it isn't already. Then select the time and day sometime you like (in daylight). Finally, pick on the "Launch Geographic Location" button shown to the left. This will open a dialog that will allow you to pick the nearest city to you or your exact co-ordinates.

As you set it, you should see the results in your drawing area. If it seems too bright, you can also adjust the intensity of the Sun. Try different settings until you get the look that you like. Note: If you selected Las Vegas as your Location, and you have lawn, your water bill will be quite expensive.

To render the scene, type in RENDER. You should get something like this:

Now that you see how it works, you can try different settings. Earlier in the day should produce longer shadows than at midday.

You can also control the sun from the ribbon.

The button the left for Sun Status will turn the sun On or Off (in the image above, it is on). This is a quick way to work with the sun. You can also type in SUNSTATUS and give the variable 1 (on) or Zero (off).

Spotlight

The next type of light to add is a spot light. We're going to add a safety light above the door for night time. First you want to change the background from the sky image to night. Instead of using another image, choose the gradient option in the View Manager > Background Option. Try to get a black to dark blue gradient.

If you perform a render now, you will get a nice twilight background and generic lighting.

For something a little more dramatic, it's time to add a spotlight. This will be placed under the peak of the roof and point straight down.

Look for the Lights Tool Panel on the Render ribbon.

This is easy enough - just click on the button and you will have the choice of where you want your light and what direction you want to point it. In this example, pick the endpoint (osnaps) under the peak of the roof and point straight down to the ground (ortho).

Once your light is placed, press < ENTER >. Now select the light glyph and you will see the default spread of the beam that the light will cast. (You might want to switch to your SW ISO view first).

Radiating from the glyph are two cones. The outer one is for falloff, the inner one is for hot spot. Think about how a flashlight works. You have an intense beam in the middle, then it dissipates out to the sides. By clicking on the bottom of the cones, you can adjust these settings easily.

Make some adjustments (go back to your pers view) and then perform a render. Pretty cool, eh?

Point Light

Another light option is a point light. Think of this a light bulb you would have in a reading lamp. Point lights radiate light in all directions evenly (unlike the directional spotlight). In this example, we're going to add a point light inside the building and let its light shine out the windows. We'll keep the twilight look.

From the same light tool panel that you used to place the spotlight, select Point Light and place inside the building in the larger room. Check from other views to make sure that you placed it correctly. You may find that you need to move it. Once you have it placed, perform a render.

You will probably find that the light isn't very bright. In fact it needs to be brighter to show through the windows. Click on the point light glyph and press CTRL+1 to bring up the properties palette.

In the image above, you can see the I have changed the Intensity Factor to 6. This should make the light bright enough to be seen. Change this setting in your drawing and try another render.

Below is what I have after moving the view slightly (with 3DO) to show more of the ground where the light from the window hits.

Now that you have a decent looking image, you can try some more settings. try increasing or decreasing the Intensity Factor for the Spotlight. Try adding another point light inside. Remove the interior door to get light into the small room. Try adding a street light to light the exterior of the building a little. Add a Distance light off to the side and try different intensities. Yes, I know I didn't show you how to add a Distance Light, but I believe that you can figure it out now (distance light is the easiest).

To see how many lights you have in your drawing and access them quickly for changing settings, click on the bottom right corner of the Lights tool panel.

Draw a light for the safety light and put the spot light where the bulb should go. Add some window panes to get more dramatic lighting.

The most important thing with lighting is to experiment. Try different locations and settings. Now that you know the basics, it's up to you to explore.

Render Settings

Now when you render a final image, there are many options available to you. Mostly it depends on the end use of the rendering.To adjust these settings, type in RPREF (Render > Advanced Render Settings...) to get this palette full of options.

To get a good quality rendering like the one above, set the top setting to Presentation. This will set the defaults to the best settings. Make sure that you have materials and shadows on. Render out to the window and choose the size that you want it to be. Once you have the setting you want, type RENDER again and view your results. If you like what you have done, you can save an image file from the render window.

That's the basics of rendering, practice with different settings and even experiment with light.

Once again, you have learned some easy tools that will allow to produce a good rendering of an object. Of course there are many variations and a lot of detail would go into a larger corporate presentation, but it only takes time, practice and experience.

For practice, many people will measure out their home and model it and then render it. This is a great exercise. Also, here is a good site that offers some more advanced 3D exercises.

Lesson 4-1: AutoCad Template Files

2011-04-20T09:15:00.000-07:00

Topics covered in this Lesson:
Template files | Creating Templates

Whether you know it not, you have already used templates to begin a new drawing. AutoCAD uses a template every time it starts up. If you do not designate your own template, AutoCAD will use a default one.

A template is a drawing file that includes some of the following settings:

Unit type and precision (DDRMODES)
Drawing limits (LIMITS)
Snap, Grid, and Ortho settings (Status Bar)
Layer organization (LA)
Title blocks (Tutorial)
Dimension and text styles (DDIM, ST)
Linetypes (LT)
Common blocks (Tutorial)

In most cases, you do not want to set these things every time you begin a drawing. By having a template with all of these parameters pre-set, you can work more efficiently, faster and consistently. There is no difference between a template file (DWT) and regular DWG other than the extension.

Most CAD businesses use a company-wide template that is updated from time to time. Occasionally, you will use a client's template. When you start a project, you will be told which template you are to use.

Creating a Template

To create a template drawing, you first have to set up any parameters that you feel you would need (see the list above) in a regular drawing. Once you have this, you can save your drawing as a template. Do to this, press CTRL+SHIFT+S to get the ‘Save As' option.

You will see this dialog box:

You have to change the ‘Files of type' setting from a DWG file to a DWT (template) file.

Once you've changed this, make sure you save it in the folder where you can load it later.

To use the template for a new drawing, type NEW to start a new file and select the template you want.

Lesson 4-2: Using Osnaps In AutoCad

2011-04-20T09:09:00.000-07:00

Topics covered in this Lesson:
Object Snaps.

Object snaps (Osnaps) are one of the handiest tools in AutoCAD. Without them, you would have a lot of trouble doing even the simplest dimension accurately. Before discussing how they are used, first think about what they are. Their name, "object snaps" means that they snap to objects, or more precisely, they snap to specific parts of an object. A line for example has 3 points that you can snap to: a midpoint and two endpoints. A circle has 5 points: a center and 4 quadrants. To use Osnaps effectively, you must know what points an object has that you are able to snap to.

There are also some Osnaps that are not precise. These allow you to snap to (sometimes) arbitrary points along an object. These would include nearest, tangent, perpendicular and to some extent, intersection.

There are two different ways of working with Osnaps; in running mode or invoking them individually as required. Running Osnaps mean that certain ones are turned on and running in the background. This means that they are available when needed in the middle of a command.
Sometimes you may need one Osnap that isn't one you have selected in running mode. In this case you can turn it on for one-time use. There are a few ways of doing this: you can select the icon for the Osnap you need, you can type in the 3 letter shortcut, or you can bring up the Osnap dialog box and turn it on ('OS), or even shift+right-click and pick from the menu. I recommend learning the 3 letter shortcuts and typing them in when required. This is generally the fastest way to get your Osnap on, plus it doesn't leave it on if you don't need it afterwards. Having the icons up your screen works, but takes up valuable screen area. Try each method and see which one works best for you.

In most cases you want to turn on all the osnaps while drawing as you could accidently snap to a point you don't want. For example, the endpoint and a perpendicular point could be very close - so you need to be careful when using perpendicular.

Below is the Osnap dialog box with a detailed listing of how each one is used.

ICON	SHORTCUT	SETTING
	TT	TEMPORARY TRACK POINT
	FROM	SNAP FROM
	END	ENDPOINT
	MID	MIDPOINT
	EXT	EXTENTION
	CEN	CENTER
	NOD	NODE
	QUA	QUADRANT
	INT	INTERSECTION
	INS	INSERTION POINT
	PER	PERPENDICULAR
	TAN	TANGENT
	NEA	NEAREST
	APP	APPARENT INTERSECTION
	NON	NONE
	OS	OSNAP SETTINGS
-	M2P	Middle of 2 points

The Osnap toolbar is only available when you are in the AutoCAD Classic Workspace. You will see the icons when you Shift+Right-Click while in a command.

The 3 letter shortcut is in bold in the list above, notice that it is the first 3 letters of each Osnap.

Also note the Osnap symbol beside each setting in the image of the dialog box above. These will be visible on your screen as the osnap becomes active.

LISTING OF OSNAPS MODES

TEMPORARY TRACKING - While not really an Object Snap, this option allows you to pick any point on the screen and track from there. This point can be on an object or not.

FROM - This option allows you to select an Osnap and use it as a reference point. Very similar to Temporary Tracking.

ENDPOINT – This snap is used to get to the exact endpoint of a line, arc or other object that has a definite ending to it. This should be used for joining lines, and dimensioning. In general, you would want this on as a running Osnap in your drawing. The endpoint Osnap is indicated by a small square.

MIDPOINT – This is used to find the exact middle of any object that has a beginning and an end. All lines and arcs have a midpoint. (Circle have a center, not a midpoint.) This is also a good Osnap to have in running mode. The midpoint Osnap is indicated by a small triangle.

CENTER – The center Osnap is used to find the exact center of circles, arc and ellipses. This is also a good Osnap to leave in running mode. To pick the center point, you have to select the object itself, and not an area in the middle of the object. The center Osnap is indicated by a small circle.

NODE – Nodes are points. The are created using the point command. They are also created when an object is divided. A node Osnap is indicated by a circle with angled crosshairs in side.

QUADRANT – Quadrants are the ‘corners' of circles and ellipses. Arcs can also have quadrants. The quadrant Osnap is indicated by a diamond. The are four quadrants on every circle.

INTERSECTION – The intersection Osnap appears wherever two objects cross. If you select one object you'll see a cross with three dots indicating that you have to select a second object to find an intersection. Pick on the second object and AutoCAD will find the intersection for you. This is handy when you have a lot of lines in the same area. An ‘X' indicates the intersection Osnap.

INSERTION – The insertion Osnap will snap to the insertion of points of objects such as blocks, text and attributes. Each object will be different depending on how it was created. The insertion Osnap is shown as two small, offset squares.

PERPENDICULAR – The perpendicular Osnap is used to draw a line from one point to another point at a right angle (90degrees) to an object. This Osnap can save you having to trim or extend afterwards. If you use the perpendicular Osnap for starting a line, you will get the indicator with 3 dots telling you that the next point is needed to establish the starting point. The perpendicular Osnap is indicated by a square with two extending lines.

TANGENT – Tangent Osnaps are used on circles, arcs, ellipses and splines. A line tangent to an arc gives you a smooth line off the curve. If you select the tangent Osnap as the first point, your indicator will have three dots following it. This means that the tangential point can not be established until the second point is given. The tangent Osnap is shown as a circle with a line across the top of it.

NEAREST – The nearest Osnap does just as the name implies: it will find the closest point on an object relative to where you started. This is handy for measuring distance and drawing quick lines, but can lead to erroneous results when dimensioning or drawing. This Osnap should rarely be used in running mode, and never for dimensioning. The nearest Osnap is indicated by a triangular hourglass.

APPARENT INTERSECTION – The Apparent Intersection Osnap is used when two objects appear to intersect on the screen, but do not truly intersect in 3-D space. It also works when any two objects do not intersect, but you need to find the point where they would. This Osnap will also find the true intersection of two crossing objects. This Osnaps has different indicators depending on which mode is needed at the time.

NONE – This command is used to turn off any Osnaps that may be on in running mode. You can also disable your Osnaps by hitting the F3 key, which would be a faster way of doing this.

In AutoCAD 2005, there is a new Osnap "Midpoint Between 2 objects" - it's not in the Osnap dialog box, but can be invoked when needed by typing "MTP" or "M2P" or using the shift+right-click option.

Command: L LINE Specify first point: MTP
First point of mid: < PICK > Second point of mid: < PICK >
Specify next point or [Undo]: (Select point or enter to end)

OTHER NOTES ABOUT OSNAPS:

Osnaps are only available when you are currently in a command.

Toggle Osnaps on and off by using the F3 key. If you do not have any Osnaps on in running mode, the F3 key will invoke the Osnap dialog box.

Get into the habit of working with the same 2 or 3 Osnaps in running mode whenever you are drawing. The more consistent you are, the easier it is to keep track off while working.

When dimensioning, you must be VERY careful where you are snapping to. Make sure that you are not using the nearest, perpendicular or intersection Osnaps unless you specifically require them. Below is an image that shows a common mistake of dimensioning to another dimension line and not the object. Often you will catch this if your measurement is an odd number (should be 11 in the example below).

If you have a lot of objects in one area, and need a particular Osnap, use the TAB key to cycle through all available Osnaps in the area. As you hit the TAB key, you will see that the Osnap location changes and AutoCAD highlights the object you would snap to.

Zoom in when in doubt. Make sure that you are snapping where you need to. Snapping to the wrong part can cause catastrophic events.

If you want to invoke the Osnap dialog box while in the middle of a command, type in ‘OS at the command prompt. You can then make your changes and then continue with the command.

CHANGING THE OSNAP'S APPEARANCE

If you want to change the appearance of the Osnap indicators, such as size or color, bring up the Osnap dialog box and pick on the Options button on the Osnap Dialog box).

On the left side of the dialog box, you can set the 'look' of the Osnaps when you are using them.

The Marker, Magnet and Snap Tip should be left on. Marker shows the active osnap. Magnet 'snaps' you into position when you are near. The Snap Tip is a small text box telling you which osnap is current. Leaving the aperture box off, makes it easier to see the snap points.

The Marker Size is a matter of personal preference, but the default seems good to me.

The color of your Osnap might need to be changed depending on the color of the objects you are working with or screen background color.

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Lesson 4-3: Line Types And Line Type Scale

2011-04-20T08:44:00.000-07:00

Topics covered in this Lesson:
Linetypes | Linetype Scale | Lineweights

When you have been drawing in AutoCAD during these tutorials, almost all of the lines have been continuous. This is a particular linetype. Most simple drawings can be drawn with just this one linetype. More advanced drawings will require different linetypes such as center lines, hidden lines, phantom lines and others.

When you first start AutoCAD, the default template has only one linetype is available. This is the continuous linetype. AutoCAD has many more available, but only loads in one to start with in order to keep the drawing file size smaller. If you need a different linetype, you must load it into your current drawing. As is usually the case in AutoCAD, there are a few ways to do this.

Command - Keystroke - Location - Result
Linetype - LINETYPE / LT, Home > Properties >Linetype - Opens the LINETYPE dialog box
Linetype scale - LTSCALE / LTS, None - Allows you to set the linetype scale globally.
Lineweight - LINEWEIGHT / LW - None - Set line weight globally

Invoking the LINETYPE command brings up the Linetype Manager dialog box as shown below.

You'll notice that it is similar to the layer dialog box.

Instead of creating a new linetype (like you would a layer), you will have to LOAD it into your drawing. AutoCAD has many different linetypes that you can load, as well as giving you the option to create your own. (This will not be covered in this lesson.) To load a linetype, press the Load... button that is towards the top-right corner. When you do this, you'll see another dialog box appear (shown above).

Notice that AutoCAD is giving you a choice of different linetypes as defined in the acad.lin file. Scroll through the list to see what options you have available. You'll see the most common ones (hidden, center, etc) as well as some that are only for certain applications. Click on the Hidden linetype and then press OK.

Adding a linetype to your drawing is that easy. Notice that there are three different hidden linetype options: HIDDEN, HIDDEN2, HIDDENX2. All of these are valid linetypes, but as you can see from the samples shown in the right side of the dialog box, they are slightly different. Which one you choose is up to you. Remember one thing though. If you pick HIDDEN2, then you should also pick CENTER2, if you need a center line. This will keep your linetype scale consistent. Only change your linetype scale singly if you have a specific reason to.

Here is an example of 3 different linetypes:

LINETYPE SCALE

Your linetype scale determines how the linetype is displayed and plotted. Depending on your linetype or original area you set up, you may have to change it. This is one more reason, why you should set up your drawing properly from the beginning. If you need to change your linetype scale, type in LTSCALE and try different values to get the look you want. You can also change you linetype scale from the LINETYPE dialog box by changing the value in the Global Scale Factor box.

Note: you can change the linetype scale separately on each object, but this is not recommended as it can be very difficult to keep track of, and therefore lose consistency.

Here is a single linetype (hidden) with 3 different linetype scales applied. Notice that the line with a LTS of .5 has lines and dashes that are 1/2 the size of line above it. The line with a LTS of 5 has lines and dashes that are 5 times longer.

You can change the linetype of an object by changing its properties, or use the droplist of layers on the main drawing screen. This is a simpler, quicker method - just select the object, then pick the linetype from the list.

Linetypes can also be controlled by putting them all one layer and using the ByLayer option. For example, you could have all of your hidden lines on one layer so you can turn them off all at once or give them a light lineweight.

LINEWEIGHTS

Another property of lines is their lineweight, or how wide they display on the screen and when printed. One common example of a heavier lineweight would be a border around a title block. Some times, you may use a lighter lineweight for hatching. But whatever you use them for, they are powerful display options.

Here are the range of lineweights available (There are more options in between):

The methods for changing the lineweight for objects is similar to the ones for linetypes (above). There is also the option of turning the lineweight display on or off. Just click on the LWT icon of the status bar. Below the icon indicates that lineweights are shown in the drawing.

Type in LW to access the Lineweight Settings Dialog box.

The options are quite straightforward, but you also have the option of displaying lineweights or now (Display Lineweight) and changing the default display lineweight. By working with different linetypes and lineweights you can make a drawing clearer. Some people will make their objects have a heavier lineweight than the dimensions to make them stand out better.

Extra Practice: Make an isometric drawing that uses a heavier lineweight for the main objects and a lighter lineweight for hidden lines.

Lesson 4-4: Autocad File Formats

2011-04-20T08:12:00.000-07:00

Topics covered in this Lesson:
File Formats

Every file in a computer is created as a particular type or format. For example, a Corel WordPerfect letter file is created as a WPD file. A standard AutoCAD drawing is created as a DWG file. The difference is the way that the application program recognizes the file. Each file type also has a distinct structure so that the program that created it can read it correctly.

In the ‘olden' days when DOS was the common operating system, all files had a maximum of 8 characters in their name, followed by a period, followed by the extension. The extension was a 3-letter ‘code' indicating the type of file.

Example: DRAWING1.DWG

DRAWING1 name of the file
DWG extension

After the introduction of Windows 95, you may have more than 8 characters in a name (up to 256), but the 3-letter extension remains. Windows is even set up to hide these extensions from you in its default configuration, so you'll want to turn them on to make things easier for you..

While working with AutoCAD, it is important to know that there are several types of drawing files. Here are some of the common filetypes you will come across:

DWG - BAK - DWT - DWF -SV$ - DXF - WMF - 3DS - JPG

These are only a few of the file types that AutoCAD uses. There are many others that would be considered support files. Those listed above deal with various forms of drawing files. There are many other ways to save your drawing, but these are the common ones.

DWG – This is the standard AutoCAD drawing file format. The thing to remember is that older versions of AutoCAD cannot read files created on newer versions. The newest version can read any of the older files. If you are exchanging files with other companies, do not assume that they are using the same version you are. Some co-workers will also have older or newer versions than the one on your computer.

BAK – This is AutoCAD's backup file format. Whenever you save a drawing, AutoCAD will automatically create a duplicate backup file. This file has all the same information as the original, but a different extension. If your original file becomes corrupt, or unusable for any reason, you can rename the BAK file to a DWG file and open it as you would any other drawing file. You can set the interval for backing up your file in the Options > Open and Save tab set for as short as possible with interrupting your workflow.

DWT – This is a newer format (R14) that is used for drawing templates. Templates are the same as prototype drawings in that they contain all the setup parameters for certain types of drawings. They are essentially the same as a DWG file.

DWF – This is also a fairly new format. This is used when you want to create a drawing that is for use on the Internet or otherwise not editable. It is a Drawing Web Format. This type of file contains features that allow users to view drawings on the Web without having AutoCAD on their computer. You can also use the DWFOUT command to open the Plot dialog box pre-set to DWF setting.

SV$ - This is AutoCAD's format it uses whenever it performs an automatic save. AutoCAD will save the file automatically within a pre-determined time frame. This is set in your Options > Files dialog box. You can also tell AutoCAD where you want your autosave files to go. Most computers are set to save to the Windows/Temp folder. If you need to recover a drawing from the autosave file, just rename it to a DWG format.

DXF – This is not really an AutoCAD format but an industry standard, but one that you should be aware of. DXF stands for Drawing eXchange Format. This is a very standard format that is used but many different CAD and graphics programs. This allows users to exchange drawings even if they don't have the same program. When you use the DXF format, some objects may change their appearance when re-opened. As with DWG formats, DXF formats vary from different releases. You have the option of saving the files as a DXF or you can use the DXFOUT command, conversely DXF Files can be imported using the DXFIN command.

WMF – This is a Windows Meta File. This file can be used if you need to use this drawing in a non-CAD program. For example, you may need to add a drawing of section of a drawing to a Microsoft Word document. You would use this format to do that. You can export only a portion of your drawing with the WMFOUT command.

3DS - This is an older extension for 3D Studio Max - a high level animation and rendering program. You can import to (but not export from) AutoCAD by using the 3DSIN command.

JPG - Most people know JPG's as the common format on the internet for images. You can also export your drawing easily to a JPG now. Use the JPGOUT command and then choose between the viewport or selected objects. You may need to change your background color to white for this.

BMP - This is similar to a JPG, but exports a raster BMP file instead of a JPG. Use the BMPOUT command. Generally JPG's are smaller and better for e-mail and websites.

PDF - Although not a AutoCAD specific file format, you can now save your drawing as a PDF (Portable Document Format) so that others can read it with the common Adobe Acrobat Reader. Use the Saveas... PDF option.

These are the common file types used in AutoCAD. The main thing to remember is that you have the option of sharing your drawing with people who don't have AutoCAD installed on their machines.

Lesson 4-5: Grip Editing

2011-04-04T00:07:00.000-07:00

Topics covered in this Lesson:
Working with Grips

By now you should be familiar with grips. These are the ‘blue squares' that get highlighted when you select an object outside of a command.

Grips are handles that allow you to manipulate the object without entering a command directly. Be aware that grip editing can lead to undesired results if you are not careful.

The look of your grips can be changed by entering the DDGRIPS command. You'll see this dialog box (it's the Options dialog box: Selection tab):

Notice that you can enable or disable grips, as well as control whether they are enabled within blocks or not.

You can change the colors so that they are more visible depending on the particular drawing or background color you are working in. You can also change the size of the grip if you need.

Notice that there are two different colors for grips, one when they are unselected (but visible) and another color when they are selected, or hot.

Usually these settings do not need to be changed.

When you first start working with grip editing, I recommend that you use it for modifying your dimensions. This is an easy way to get started, as it won't affect your geometry.

Once you have mastered grip editing with dimensions, try editing your geometry and you'll find that in many cases this can be quicker and easier than using the regular AutoCAD commands.

When you first select a grip and make it hot, it turns red and you are able to stretch it to where you need it to go. Always read your command line when grip editing.

Command: < select an object >
** STRETCH **
/Base point/Copy/Undo/eXit:

You'll see that there are few options, ignore these for now and try the stretch option. You can now move that point anywhere and snap to any Osnap that you have active. This can be a quick easy way to connect lines rather than extend them. Once you have made your modification, press the escape key to deselect the grips. (Pressing the enter key will repeat the last command, which you don't want to do). You may have to press escape a few times to totally deselect the object.

The stretch option is only the first of several commands that you have available for grip editing. By pressing the space bar, you will be able to cycle through all available options for grip editing.

Command: < select an object >
** STRETCH **
/Base point/Copy/Undo/eXit:
** MOVE **
/Base point/Copy/Undo/eXit:
** ROTATE **
/Base point/Copy/Undo/Reference/eXit:
** SCALE **
/Base point/Copy/Undo/Reference/eXit:
** MIRROR **
/Base point/Copy/Undo/eXit:

The previous lines of text show what the command line would look like as you cycle through the options.

To use any of these options, you should be very comfortable using the regular commands first.

You'll notice that these other options work a bit differently than the stretch option. If you have many objects selected, you can stretch one point, but can move all the objects highlighted with grip editing. This applies to the rotate, scale and mirror options as well.

Different objects have different grips available to them. A line has 3 grips: 2 endpoints and a midpoint. You can stretch the endpoints, but if you ‘stretch' the midpoint, you move the line. You can stretch quadrants of a circle to change the radius, but stretching the center grip will move the circle. Single line text has one or two grips depending on the justification used. You can use their grips to align the text.

You can also use grips to adjust points in 3D objects. Just like a 2D object, select the solid with no commands are currently running and the grips will appear. You can then stretch grips to new points, giving you more power when editing solids.

In the example on the left, the Center grip was used to shorten the 3D solid.

In review, if you can master grips, you will be able to be much quicker at editing your drawing. In many cases you will want to make sure your Osnaps are on, to snap the grip to the correct location.

Lesson 4-6: AutoCad's Inquiry Tools

2011-04-02T07:31:00.000-07:00

Topics covered in this Lesson:
Distance | Area | Mass Properties | List | ID

AutoCAD has many tools to help you as a designer. Some of these you may have already used. The properties command gives you a lot of information about an object you have selected and allows you change most of them. AutoCAD also has some commands used specifically for pulling information from objects.

Most of these commands can be accessed from the Home > Utilities tool panel. Here is a list of those commands (click on the icon for more information) :

The first one, DISTANCE (DI), is quite straight forward. It allows you to select two points on the screen and AutoCAD will tell you the total distance as well as the changes in X,Y & Z.

Command: DI DIST
Specify first point: < SELECT ANY POINT >
Specify second point or [Multiple points]: < SELECT ANY POINT >
Distance = 12.5107, Angle in XY Plane = 25, Angle from XY Plane = 0
Delta X = 11.3228, Delta Y = 5.3208, Delta Z = 0.0000

MEASUREGEOM is used to for a few options, amond them Radius which will measure the radius of a circle or arc. Enter the command and then choose radius from the list on the screen.

With Radius selected, just pick on any arc or circle to have the radius displayed.

AutoCAD is kind enough to give you both the radius and the diameter on the screen - and on the command line:

Command: measuregeom
Enter an option [Distance/Radius/Angle/ARea/Volume] : R
Select arc or circle: < SELECT THE OBJECT >
Radius = 3.3780
Diameter = 6.7559

You are left in the command and can select another option like Angle. Now you're asked to select 2 lines and the screen will display the angle between them.

Volume measurements can be used on 3D objects or 2D objects (if you enter a height). You can either select and object or pick points.

AREA is a command that can be very useful. This can used to calculate square footage for floors, property lots, or even something like sheet metal parts. To use this command, you can type in AREA and see this on your command line:

Command: AREA
/Object/Add/Subtract: O
Select objects:< SELECT AN OBJECT >
Area = 56.7498, Perimeter = 30.6775

The default option is to pick a point on the screen. This allows you to select the four corners of a room to find the total area in square drawing units (usually inches). You can pick as many points as you need and then press enter when you're done. AutoCAD returns the area and the perimeter length. If you select the next option (object), you can select a circle, rectangle, polyline or some other closed object. You also have the option of adding to or subtracting from the initial area. You may need to find the carpeting area of a room, but exclude where you have tile. Or you may need to add several rooms together.

MASS PROPERTIES is an option for finding information about 3D solid objects. You can find out the total volume and from there calculate the weight based on volume. AutoCAD also figures out some important engineering figures for you such as the center of gravity for an object. This listing shows you all the information you can get from MASSPROP:

Command: massprop
Select objects: 1 found
Select objects:
---------------- SOLIDS ----------------
Mass: 12.0984
Volume: 12.0984
Bounding box: X: 1.8644 -- 4.1304
Y: 16.1318 -- 18.3978
Z: 0.0000 -- 3.0000
Centroid: X: 2.9974
Y: 17.2648
Z: 1.5000
Moments of inertia: X: 3646.3725
Y: 148.8749
Z: 3722.6569
Products of inertia: XY: 626.0851
YZ: 313.3141
ZX: 54.3957
Radii of gyration: X: 17.3607
Y: 3.5079
Z: 17.5413
Principal moments and X-Y-Z directions about centroid:
Press ENTER to continue: < ENTER >
I: 12.9564 along [1.0000 0.0000 0.0000]
J: 12.9564 along [0.0000 1.0000 0.0000]
K: 7.7653 along [0.0000 0.0000 1.0000]
Write analysis to a file? [Yes/No] : n

This is a lot of information, so AutoCAD gives you the option of saving it to a file after it is displayed.

LIST is an inquiry that gives you some basic information about a command. This is usually the information that AutoCAD needs to know about it to keep track of it in its database. Here is a listing of a line:

Command: LI LIST
Select objects: 1 found
Select objects:
LINE Layer: "0"
Space: Model space
Color: 1 (red) Linetype: "BYLAYER"
Handle = 2fd
from point, X= 9.2042 Y= 13.5272 Z= 0.0000
to point, X= -2.1187 Y= 8.2064 Z= 0.0000
Length = 12.5107, Angle in XY Plane = 205
Delta X = -11.3228, Delta Y = -5.3208, Delta Z = 0.0000

Here are the properties (CTRL+1) for the same line:

Notice that you can get the same information, but also have the option of changing anything that you need to.

After List, the next option is ID POINT. This allows you to select anywhere on the screen and have AutoCAD return the X,Y&Z co-ordinates for that point. Here is a listing of ID POINT:

Command: ID Specify point:

Lesson 4-7: Xref's (External References)

2011-04-02T05:54:00.000-07:00

Topics covered in this Lesson:
Xrefs

An X-ref is an ‘external reference' to another AutoCAD drawing file. One file can reference many other files and display them as if they were one. These are used in larger projects for many reasons:

They keep the file sizes down.
They allow many users to work on individual components of a project.
Every time an X-ref is loaded, it is the most recent version of the drawing.
X-ref's can be updated, added, or unattached from the main drawing at any time.
You can X-ref drawings that they themselves X-ref other drawings (nesting).

In these days of networks and the Internet, many projects are produced this way. People from anywhere in the world can collaborate on a project in real time.

The first thing to do is to ATTACH the X-ref. This means that you are linking another drawing to your current one. Do this by starting the XFEF (XR) command. When you start the command, you will see the palette shown on the left.

To attach an Xref,click on the "Attach DWG" button on the top left. (Note that you can also Xref Image files and DWF's)

The "Select Reference File" window will open: select a file and press Open. When you do this, you will see another dialog box appear.

Once you find the file, decide whether you want it to be an attachment or an overlay. An overlay will not include any of the nested X-ref's that the file may contain. Below that section are the insertion parameters. You have a choice of either defining them on-screen, or using standard defaults in the dialog box. Once you make you decisions, press OK.

Finish the Attachment by following the prompts on the command. You'll see that it is similar to inserting a block.

After inserting the Xref, you will see that the Xref Palette is updated with the new Xref.

Now that you have an X-ref, there are more options for you if you right-click the filename of the Xref.

ATTACH – Attaches another X-ref.

DETATCH – Detaches the selected X-ref.

RELOAD – Updates the selected X-ref - use this if the Xref was changed.

UNLOAD – Removes the X-ref, but retains the reference for future use.

BIND – Permanently attaches a loaded X-ref, so that it is part of the drawing.

Working with X-ref's is usually quite straightforward, but there are some things to keep in mind.

The insertion point is very important. Everyone on a project must be working on the same set of co-ordinates and insert points..

When you attach and X-ref, you insert that file's layers and blocks. AutoCAD creates new layer names based on the filename and layer name of the X-ref. In AutoCAD R14, you have a limit of 31 characters for these names. If you exceed that number, your X-ref will not load.

When you print, AutoCAD will automatically reload the attached X-refs.

If a file is moved from a location that AutoCAD expects to find it, you can browse for a new path, without having to re-attach the X-ref.

Recent versions have added more functionality to Xrefs. You can edit them in the drawing (as opposed to having to open the original file). To do this, just select the Xref in the drawing and right-click.

As you can see, there are other options to Open the Xref, Clip it (crop it down) or open the Xref Manager.

One problem in the past was the if a co-worker changed an Xref that was attached to your drawing, you didn't know and could keep working on the wrong information. Later versions of AutoCAD alert you when an Xref in your drawing has been modified by someone else.

Keep in mind that Xrefs are important and used in any major project. Practice working with them by attaching some of your previous drawings.

Lesson 4-8: System Variables In AutoCad

2011-04-02T05:48:00.000-07:00

Topics covered in this Lesson:
System Variables

AutoCAD is a complex program and one of its major selling points is that it is highly customizable. Every user will use AutoCAD differently. Some use icons, some use command line prompts. Each drawing is also different. You may have different text heights, or dimension styles from one drawing to the next. To keep track of these different parameters, AutoCAD uses a large number of system variables to do this. You have recently used one system variable: LTSCALE. This could have been changed in the Linetype dialog box, but typing LTS is easier and quicker.

A system variable is a configuration setting that can be changed by the user. Some system variables can not be changed, these are known as read-only variables. Here is an example of each:

System Variable          Current Value            Type
TEXTSIZE                0.200                  User Configurable
ACADVER                  "16" (read only)       Read Only

Most of AutoCAD's system variables are changeable. This allows for quick customization as well as easier programming.

Once you have used AutoCAD for a while, you may find that it is easier to redefine a system variable than to go through a dialog box to get the same result. In some cases, the only way to make these changes is through the system variable itself. Unfortunately, there are no shortcuts for entering these, you have to either remember them, or have a list nearby. Some of them are quite straightforward as to what they do, but some are rather cryptic and make it difficult for memorization.

**NOTE: In Level 3 (3-D), you were working with system variables to some degree.

Warning: Don't change system variables unless you know exactly what you're doing.

To see a list of all of the AutoCAD system variables, follow these steps:

Command: setvar < ENTER >
Variable name or ?: ? < ENTER >
Variable(s) to list <*>: < ENTER >

It shows you what the settings were for a particular drawing at a specific time. The list also shows you which system variables are read only. For a listing of these in AutoCAD 2008, click here.

Lesson 4-9: Date Tables In AutoCad

2011-04-02T05:44:00.000-07:00

Topics covered in this Lesson:
Creating Tables

Tables are a new AutoCAD object that is can be created and customized by the user. Tables can be used for parts lists, revision history and time you need to organize text.

Start the command and you will see this dialog box.

The labels look pretty straightforward - you can define the number of rows, columns, row height, column width and press OK. Or......you could press on the button circled above to open up the Table Style dialog box.

This allows you to create your own table style - sorry, just had to state the obvious. Give the new style a name and press "Continue".

Here, you can define the parameters (color, text height, borders, etc.) in your new custom style. This preview is used in the other dialog boxes as well. Make sure you have your Text Styles defined first. Define different styles for the Title, Header and Data. Note that you can access the Text Style Dialog as well from here.

So now that you have defined your table style, you can insert one into the drawing and enter data using the Mtext editor and tabbing through the cells. Anyone who has used a simple spreadsheet will be able to use this. One major drawback is that there is no formula function in the table.

Once the table is in the drawing, you can double-click (above) in any cell to edit it or right click (below) it for more options:

What once used to be a very tedious task in AutoCAD has become easy with this new tool. You also have the ability to copy styles from one table to another to add consistency to your drawing. Practice creating a table or two.

In case you missed it, you can also extract your data from attributes to create a table that is dynamically linked to your drawing's blocks. This tutorial is in Lesson 2-4.

Lesson 4-10: Introduction To Sheet Sets

2011-04-02T05:41:00.000-07:00

Topics covered in this Lesson:
Creating Sheet Sets

How may sheets could a sheets et set if a sheet set could Sheet Sets? Well actually sheet sets can Sheet Sets, so let's find out.

Concept:

Sheet sets are the digital version of the rolled up groups of drawings shoved in the back corner behind you. Actually they are the next logical progression from Pack 'n' Go. This time though, you are just sending the layouts and not your actual CAD file. There are a lot of variables involved when you use these, but you will give you an idea of what's involved. Sheet sets can be published as DWF's or opened up in ACAD 2005 (.dst extension).

Command KeyBoard Location
Sheetset Sheetset View > Palettes > Sheet Set Manager

Description
Opens The Set Manager

Procedure:

The first thing you would do is check that you have all your 'ducks in a row' concerning the drawings and layouts that you plan to publish. It sounds obvious, but you don't want to keep creating Sheet Sets after you find the layouts are scaled wrong, duplicated or whatever.

Start the command, SHEETSET, or use the File > New Sheet Set menu option to invoke the command (for those that like icons, it looks like the rolled up sheets shoved in the corner behind you. The palette will open as shown below - select the New Sheetset option.

After that , you'll see what could possible be the largest dialog box you've ever seen with so little info:

In this example, use some existing drawings that are part of the default samples provided when you installed AutoCAD. you Press "Next" and get taken to Step 2.

This seems fairly simple, give your set a name(1), a description(2), tell AutoCAD where to save the file(3). There is a button for "Sheet Set Properties" that gives you some more options on the set (below) - you can even create your own custom fields here.

For the sake of simplicity, this lesson will not cover this, but it is straightforward to create your own fields.

The next tab is where you can select the "folders" where your drawings are saved and add them to the Set. In your AutoCAD installation folder, select the sample folder shown below.

You now can turn on or off the layouts as you need to them. In this example I have excluded the section layouts.

The last step is to confirm what you just did in the final tab of the wizard.

You see a list of layouts that will be part of this Sheet Set - if it's what you want, press "Finish".

After finishing the wizard, you are back in AutoCAD and ready to work with the Sheet Set.

If you double-click on a sheet name, it opens up in a layout tab. you have other options as well if you right-click on a sheet.

The view list (second tab down) allows you to zoom directly to any saved view that was part of the layout (a new, great use for views).

In the Publish menu there is a button that lets you "Publish to DWF". This will publish whichever Sheets you have highlighted (all in one file). You can also right-click and select Publish for individual sets.

In the "Details" section, you have the option of either viewing the file information, or a thumbnail.

Of course there is a LOT more to these, but this lesson is aimed at explaining the concepts behind the command.

Lesson 4-11: Modifying And Creating Dimensions

2011-04-02T01:38:00.000-07:00

Concept:

A drawing needs to contain certain information. Most drawings will show you what the object is (as clearly as possible) but won't tell you everything unless you dimension it. Would you agree to buy a house just by looking at the floor plan if it wasn't dimensioned? Would manufacturers know how to build your product if you didn't dimension it? You can see how important it is that a drawing used to convey information must have clear, accurate dimensions.

In previous lessons, you have done some dimensioning (first was Lesson 1-8). To continue with this lesson, you should at least have a good concept of basic dimensioning.

There are many ways to dimension a drawing, each drafting discipline has it own set of "rules". For example, a drawing of a gear would use a different style of dimensioning than that of a subdivision. My background is in mechanical drafting, so I use that discipline as an example of how to work with setting your dimensions to work with your drawing.

Below is an example of how a drawing can be dimensioned:

As you can see, on a simple drawing like this one, only 8 dimensions are needed to convey all the information about the size and shape of the object. With a little more information you can have everything you need to build it. This is the default style you get with the AutoCAD template.

Below shows the same drawing, but with added tolerances and note about what the object is made out of.

The changes in the dimensions above were done easily using the DDIM command. This command opens a dialog box for changing the parameters of your dimensions. In this example, the text style was also changed.

The great thing about AutoCAD is that it is very versatile. In the case of dimensions, you can modify any component that is part of it. Below are the names of various parts of a dimension:

Also, you can modify the dimension text dramatically, here are some examples:

The Dimension Style Manager
So now that you have seen what can do - how do you do it? All options are available in the DDIM (Dimension Style Manager) dialog box.

On the left is current style for working with (highlighted in blue).

In this lesson, you will create a new Dimension Style and use it in a drawing. From there, you should try different styles and get familiar with the options. Most companies these days will have a standard style (or set of styles) to use on drawings, but this is a very important tool to know if you want to turn out professional looking drawings.

Start but invoking the DDIM command and press the NEW button to open the small dialog for entering the name of the style you are creating. In this example I used the name "DIMSTYLE 1".

Make sure that "Start with" has "Standard" as its setting. Press the Continue Button when everything is set. This will open the dialog box for settings, so just press OK to close it for now.

Back at the "Dimension Style Manager" dialog box, you will see that the new style you created is listed at the top (left side). To modify it, select the name, then press the modify button. The dialog box opens and click on the second tab (Symbols and Arrows).

As a general rule, I recommend not change much on this tab - especially when you're learning. Set as defaults, the dimensions are sized proportionately, if you change the setting on one parameter, your dimension can look 'off-balance'. For example, you could end up with huge arrows and small text. For the purposes of this lesson, the only thing that will change on this tab is the arrowheads. Select something other than the standard. You'll also see that you can set the colors, but just like regular objects, it's best to leave them set to "Bylayer" - and make sure you have a separate layer for all dimensions.

Go to the third tab (Text).

Start up the Text Styles dialog box by pressing the button with the ... next to the text name. Create a new textstyle using RomanS and a width of 0.8 and call it "DIMTEXT". (For more info, see Lesson 1-8.) Close the Text Styles dialog box. Select DIMTEXT as your text for dimensions as shown.

The great thing about this dialog box is that it shows you a preview of what your changes will do the final dimension in the top right window. In the bottom right, select ISO as the Text Alignment option. Try some other changes to see their effects in the preview, then end with the settings as shown below:

So far you haven't changed much, but you've seen the options available in just 2 tabs. Click on the next tab to continue.

As a rule, I leave this tab alone. AutoCAD does a good job of placing and fitting dimension where I want them. If I don't agree, I usually just use grips to edit the placement. Click on the next tab (Primary Units) to continue.

In the Primary Units, you find some of the more common parameters that need to be changed. Precision is very important. First off, you usually don't need to show 4 decimal places. If you do show 4 decimals places and send your drawing off to the machinist, you are asking him to manufacture the part to within 1/10000 of a unit - which can be a very expensive mistake. 3 Decimal places is usually enough - or less for rougher jobs.

Also, I have added a couple of other changes; adding trailing zeros and a suffix denoting the units. Note how angular dimensions have a separate section - make sure you don't neglect them.

Make the changes you see above and check the preview after each change. In this tab, you can also set the overall scale of your dimensions. This can also be done using the DIMSCALE command.

The next tab (alternate units) is used if you want to display two different units in your dimension. For example, you can draw your drawing in imperial inches, then dimension with inches as your primary units and add the alternate units behind. Skip this tab for now and go on to the last tab (Tolerances).

In this example, you will set the tolerances to be +/- .05 units and display them at 80% of the primary units. Sound easy? It is. Look at the image below to see how this is done.

Once again - preview shows you how it will turn out. Click OK to close the dialog box. At the original Dimension Style Manger, press the name of your new style, then click the "Make Current" button. Close the dialog box to go back to your workspace.

Draw the wedge shape at the top of the less and dimension it using your new Dimension Style. It should look something like this:

Now you have the basic understanding of how dimensions work, you can experiment and work with other styles.

Here are some common rules about dimensioning:

Keep them on a separate layer.
Dimension towards the end of your project or you could be moving them as you add more objects.
Use your Osnaps and confirm what you are snapping to.
Assign them a unique co lour in the drawing, and use that co lour in all of your drawings to make it easier to identify dimensions (especially when zoomed in close)
After you create your first dimension, AutoCAD creates a new layer called "DEFPOINTS". This is used only for the small points you see at the end of an extension line. This layer will not print - so be sure not to draw on it.
Keep even spacing between you dimensions and between your dimension and your object lines. Use DDE while placing dims.
Try not over lap lines (either object or dimension).Use enough dimensions to make sure that all measurements are there - one dimension left out can hold up a project.
Try to keep dimensions outside of the objects you are dimensioning.
For clarity, don't over-dimension.
If you need to override one dimension (perhaps a unique suffix), you can change it in the properties (select > right click > properties)

Dimensioning in Layouts
If you are familiar with Layouts (or Paper Space) as shown in Lesson 2-4, you can continue with this lesson which will explain dimensioning in Layouts.

Using the same wedge shape from above, delete your dimensions and then scale the wedge up by 24X.

Go into your Layout and use a zoom factor factor of 1/12xp for your viewport.

Start dimensioning your lines. AutoCAD now does a great job of dimensioning in Layouts. It will recognize the scale of the viewport and find the correct size of the object you are dimensioning.

I recommend doing all of your dimensioning in you Layouts. There are a few reasons for this:

It leaves your model space free of dimensions
For 3D objects, this system is MUCH easier.
You only need one size of dimensions for full view and details.
You can add your title block, notes and dimensions in one area.

I hope that this lesson has given you the ability to create professional, accurate dimensions. Like everything else in AutoCAD, practice make perfect.

For more practice, create a simple floor plan and create a dimension style using Architectural units and 'ticks' instead of arrows. Use a precision of 1/2". Here's a very simple Architectural drawing using this style.

Lesson 4-12 : Introduction To Customizing AutoCad

2011-04-01T01:21:00.000-07:00

Concept:

One of the great things about AutoCAD is that it can be easily customized to suit the individual user. By now, you have seen how you can change the osnaps for example, but you can change a lot more than that. This lesson will introduce you to some of the customization options you have.

Keyboard Shortcuts (you will need to have the express tools installed)

So far you have been using AutoCAD's default shortcuts. This section will show you how you can create your own to help your productivity. All shortcuts are stored in the acad.pgp file. This file is loaded into AutoCAD every time you start the program. It is now easy to edit thanks to an express tool names ALIASEDIT.

Type in this command and you'll see a dialog box pop up. Press the Add button.

In this example, I have created a shortcut for MATCHPROP which is usually MA (I find that two keys on opposite sides of the keyboard slow me down). Since N is not used for anything, I find that one letter is more than twice as fast as two. Type in what you see and press OK.

Now press Apply so that the changes take effect. You'll see this dialog box warning you that you are about to overwrite your acad.pgp file. Press yes, ONLY if you are sure you did the correct changes.

Press Yes and you will see a message pop up that you have saved your changes and that your current AutoCAD session has been updated. That means that you can now use the shortcut you just added.

CUSTOMIZING THE INTERFACE

Quick Access Toolbar

The quick access toolbar is the row of icons at the top of the screen. You'll find Save, Print and other common commands there. One that you won't find is Save as. This is a pet peeve of mine, so I added it. It's easy and you can do it to. Use this method for adding any commands to this toolbar.

Navigate the Ribbon to Management > Customization > User Interface. You'll see this dialog box come up.

In the top left section, look for the Quick Access Toolbar 1 folder. Then look for the Save as command in the list in the bottom left. Drag the command up to it's desired position on the toolbar. Press Apply. Your toolbar should now look like this.

If you have read all the tutorials, you'll know that I don't recommend using icons. Still there are sometimes you may want to. Perhaps the command isn't used much, but you want easy access to it. Perhaps you can't create a shortcut for the command. There could be a few reasons, but here is how to create a new toolbar with the icons you want.

With the CUI dialog box open, right click on Toolbars and select New Toolbar.

Once you have your toolbar added to the list, drag a command up to it. I've decided that I want to have a toolbar with an Update Dimensions on it to save me some typing. Once you have some commands on your toolbar, press Apply to see your new toolbar.

Now you will add icons to your new toolbar. Right-click a toolbar and select Customize again. You'll see all the commands listed. You can now drag and drop an icon from that list to your custom toolbar. For this exercise, look at the list for commands you don't recognize and add them to your toolbar so you can try them out.

Right-Click Customization

You can also control how your mouse works. By default AutoCAD displays a menu when you right click outside of a command. To do this, type OP for options and go to the user preferences tab. Select the "Right-Click Customization" button. You'll see this dialog box.

For example, you should find that using right-click as and 'enter' will speed things up. Unless you frequently use the menus, you should switch to this.

These are just a few ways that AutoCAD can be customized. You can create custom hatch patterns and linetypes - even fonts. Other options include programming to automate tedious tasks in VisualLisp, VBA or C++(ARX). As you get more familiar with AutoCAD, look into these options.