3D Viewing Procedures That Are Similar to 2D

Many 3D viewing procedures are similar to their 2D counterparts. For example, you can change a view's area using the same tools as for 2D. Tools such as the Window Area, Zoom In, and Zoom Out view controls are used.

• Fitting Views in 3D - The Fit View view control has following 3D-specific setting.

  Expand Clipping Planes

  If on, the view's Display Depth is adjusted, along with the view origin and magnification, so that all elements on levels that are on for the view are displayed.

  Note: When a clip volume has been applied to a view, the Fit View tool has no effect on the volume displayed in the view, it merely fits the view to the elements contained within the applied clip volume.
• Rotating Views in 3D - Typically, the Rotate View view control is used in 3D to rotate a view to one of the standard views as well as to custom orientations.

  When rotating views in 3D, an important point to consider is the axis about which you want the view to rotate. By default, the pivot point is the center of the view, at the active depth. If the active depth is far behind the elements in the view, then you can quickly rotate the geometry out of sight. You can, however, move the pivot point to another location prior to rotating the view (see To move the pivot point for dynamic view rotation).

• Panning Views in 3D - Panning in 3D models, using the Pan View view control, gives you two options for determining the amount to pan the view. If Dynamic Display is off, a dynamic cube is displayed between the origin and the pointer (rather than an arrow as in 2D), indicating the distance and direction that the view will be moved. If Dynamic Display is turned on, then the elements in the view are panned dynamically.

3D-Specific Viewing Procedures

In addition to the familiar 2D viewing procedures, in 3D you can:

• Limit the depth of the view volume using the Set Display Depth view control.
• Change the perspective angle of a view using the Change View Perspective view control.

Window Volume

You can define a volume of a model to display in a view, using the key-in WINDOW VOLUME. After entering the key-in, you enter two data points that define diagonally opposite vertices of a rectangular volume, then select a view in which to display the information. In effect, this key-in works in a similar fashion to the Window Area tool, except that the z value (depth) of the defining points is taken into account.

Typically, this key-in can be used to display a part of an existing model, where you can snap to existing elements to define the required volume.