By default, the program creates new two dimensional objects with a zero elevation and thickness. The easiest way to create a three dimensional object is to change the elevation or thickness property of an existing two dimensional object.
The elevation of an object is its z coordinate position in relation to the xy plane in which the object is drawn. An elevation of 0 indicates that the object is drawn on the xy plane of the current UCS. Positive elevations are above this plane; negative elevations are below it.
The thickness of an object is the distance it is extruded above or below its elevation. A positive thickness extrudes the object upward in the positive z direction of the object; a negative thickness extrudes it downward in the negative z direction. The thickness is applied uniformly to the entire object. You can extrude any two dimensional object into a three dimensional object by changing the thickness of the object to a nonzero value. For example, a circle becomes a cylinder, a line becomes a three dimensional plane, and a rectangle becomes a box.
Two-dimensional entities with thickness added
You can create three dimensional objects using any of the following methods:
Draw two dimensional objects in three dimensional space.
Convert two dimensional planar objects into three dimensional objects by applying elevation and thickness.
Convert two dimensional planar objects into three dimensional objects by revolving or extruding.
Create three dimensional objects such as boxes, cylinders, cones, domes, spheres, and wedges.
You can change the default elevation and thickness values to create new objects with an elevation and thickness already applied.
To set the current elevation
Type elev and then press Enter.
Specify the New Current Elevation, and then press Enter.
Command line ELEV
To set the current thickness
Choose Fomat > Thickness.
Specify the New Current Value For Thickness, and then press Enter.
Command line THICKNESS
To set the current elevation and thickness using a dialog box
Choose Tools > Draft Settings.
Click the 3D Settings tab.
To change the current thickness, in the Current 3D Thickness box, type a new thickness value.
To change the current elevation, in the Current 3D Elevation box, type a new elevation value.
Command line SETTINGS
ELEV: Sets elevation and extrusion thickness of new objects
PROPERTIES: Controls properties of existing objects
System Variables Reference
BACKZ: Stores the back clipping plane offset from the target plane for the current viewport, in drawing units
FRONTZ: Stores the front clipping plane offset from the target plane for the current viewport, in drawing units
THICKNESS: Sets the current 3D thickness
VIEWMODE: Stores the View mode for the current viewport using bitcode