Chapter 3 Three-Dimensional Transformations
3-7
3
Three-Dimensional Transformations
Detent positions
The interval between successive detents depends on the
transformation involved, as shown in the following table.
Resetting of parameter values set in the source
coordinate frame
After setting up a three-dimensional transformation in the source
coordinate frame, if you switch to the target coordinate frame the
setting values in the source coordinate frame are converted to
values in the target coordinate frame. When you switch back to
the source coordinate frame, the original source coordinate frame
values are reset to zeros.
Specializing the Effect of the Trackball and Z-Ring
You can restrict the axes controlled by the trackball and Z-ring, or
constrain the way in which the image moves.
Restricting a transformation to particular axes
To restrict the effect of the trackball and Z-ring on the
transformation to particular axes, press one or two of the X, Y and
Z buttons, turning them on.
Restricting a transformation to orthogonal directions
To restrict the trackball movement to orthogonal directions (i.e.
along the x- or y-axis only), press the ORTHG button, turning it
on.
The image moves only in that of the x- and y-axes in which the
trackball movement is greater.
Function
Detent interval
Movement
1.0
Rotation
0.125 (45°)
Movement of rotation axes
1.0
Size change
0.25
Aspect ratio change
0.1
Perspective change
0.01
