This function allows the user to enter the accurate rotation angle. Clicking on this menu, the program will pop up a dialog box, as shown in Figure 4.9.1.

Figure 4.9.1  User Define Rotate View dialog box

If Virtual Rotation is selected, fill in the textbox for X, Y, and Z with data. Click APPLY, the view will rotate by the corresponding angle about the X, Y, and Z axis. If Screen Rotation is selected, the rotation axis is the screen rotation axis.

When Define Rotate Center under Option is selected, if Use Previous Rotate Center option is toggled on, after clicking APPLY, there is no need to select the rotate center again. If this option is toggled off, after clicking APPLY, the program will prompt the user to select a new rotate center. If Define Rotate Center under Option is not selected, the default rotation center is the local coordinate center or screen coordinate center.