Reverses the last change made. Undo is a repetitive command.

The number of undo steps is defined in the system options.

	Note
	For very large jobs this may slow you down and consume a lot of disk space.

Activate Undo either by selecting this option from the Edit menu, by pressing Alt-BackSpace, or by pressing Undo shortcut button.

Recalls the last Undo change. Redo is a repetitive command, and can be executed only after pressing Undo , or a previous Redo. Losing the Undo information will cause the loss of the Redo information.

Activate Redo either by selecting this option from the Edit menu, by pressing Shift-Alt-BackSpace, or by pressing Redo shortcut button.

Deletes the marked entities from view and sends them to the system clipboard.

The clipboard may be treated as an additional datastack, holding the entities sent to it as raw material ready to be restored at the desired time. A Cut entity disappears from the screen.

An element must be marked before it can be Cut. Select Cut from the Edit menu or press Ctrl-X to cut an element.

Takes the entities and sends them to the system clipboard in a similar manner to the Cut command. However, all entities remain on the drawing.

An element must be marked before it can be copied. Select Copy from the Edit menu or press Ctrl-C to copy an element.

Takes the system clipboard contents and inserts them into the drawing using the original coordinates.

Select Paste from the Edit menu or press Ctrl-V to paste an element.

To delete an object,

Select Delete from the Edit menu or press Delete to delete.

Delete is recoverable with the Undo command.

Restores all the marked elements to an unmarked state. This function is useful to delete or cancel marks for a large number of grouped entities without changing the display zoom.

Select Unmark All from the Edit menu or from the toolbar.

Select the material you want to add to your material collection, and define the different lighting parameters that will affect the display of the surface.

Figure 5.6. Edit Z Level Group Dialogue

Reflection	Move the dial to the left to increase the reflective properties of the surface. Move the dial to the right to decrease the reflective properties of the surface.
Translucency	Move the dial to the left to increase the translucent properties of the surface. Move the dial to the right increase the translucent properties of the surface.
Emission	Move the dial to the left to increase the emission properties of the surface. Move the dial to the right to increase the emission properties of the surface.
Color	Click on this button to change the color of a surface. A display like the one below appears. Figure 5.7. Windows™ Color Dialogue Select from the Basic colors or select Define Custom Color to choose your preferred colors. This option contains all the 32-bit range of colors from the Microsoft Windows™ operating system.
Texture	Enables you incorporate a texture from a saved picture file. Figure 5.8. Material Texture Dialogue File Name Bitmap texture file. Style Defines how to add the texture to the material: None - no texture mapping. Replace - material color will be replaced by the texture. Modulate - material color and texture color are modulated. Blend - material color and texture color are blended. Reflect - acts like the Replace function, but with a reflecting effect. Pixels Fill In In order to map a texture on a surface, the bitmap should be a square. The size of the bitmap is set to 128/ 256/ 512/ 1024 pixels. To get the bitmap into the set size it must be truncated, tiled or stretched.
	Add material that you defined.
	Delete material that you defined.
	Press Apply to make changes to the surface.

Measure evaluates vertical, horizontal and diagonal distances as well as angles between two points. After you select the measure function, a rectangle with eight control points will appear on screen followed by the measure dialog box. Move the control point to the desired locations in order to get the distances and angles between the rectangle control points. You can continue measuring until the Measure dialog box is closed.

The values in the measure dialog box can be copied into the Windows clipboard by marking the value you whish to copy (make it appear with blue background) press the right mouse button and select Copy from the pop-up menu.