Visualizing 3D Models - Autodesk AutoCAD 2013 Practical 3D Drafting and Design - page 35

• Pan : By holding down the wheel and dragging the mouse, we slide the
view, maintaining the same zoom factor.
Zooming and panning can be used transparently, in the middle of a command.
Zooming in/out with a wheel mouse is done by increments, not in a continuous way.
Sometimes this is not acceptable for small zoom changes. The ZOOMFACTOR vari-
able controls these increments. By default, it is set to 60% , that is, each wheel ro-
tation increases or decreases the zoom factor by that value. The variable is saved
in the registry. Another way for continuously changing the zoom factor is to use the
ZOOM command (alias Z ), the Real-time option. We enter the command ZOOM , press
the Enter key to accept the default option, click and hold the mouse, and drag up or
down to zoom in/out.
Orbiting the model
To view the model from different angles, we must orbit around it. The model doesn't
change, only our angle of vision changes. We may use an automatic orbit or the
commands presented next.
Automatic orbit
The easiest and most used tool to orbit a model is the automatic orbit with a wheel
mouse. Even in the middle of a command, we hold down the Shift key and we simul-
taneously hold the wheel too; the cursor changes to two small ellipses, and then, we
drag the mouse to orbit around the model. The Z axis is always vertical. It's as if we
are flying around the model, as shown in the following screenshot: