You can constrain an object so that its center maintains a constant distance from that of the constraining object.
Use either of the following methods to set a distance constraint:
To constrain an object by distance using the property editor
1. Select the object to be constrained.
2. Choose Constrain > Distance and pick the object that is to act as a constraint.
3. In the Distance constraint property editor, set the Distance value, which is a position offset in Softimage units
You can also set position offsets on any axis of the constrained object using the X, Y, Z sliders in the property editor. See Creating Offsets between Constrained and Constraining Objects for more information.
4. Translate the constraining object. The constrained object also moves, maintaining the distance you set.
or
To constrain an object by distance using constraint compensation
This method lets you keep the original distance between the constrained object and its constrainer.
1. Position the object to be constrained at the required distance from the constraining object.
2. Click the CnsComp button in the Constrain panel to set the distance offset (see Creating Offsets between Constrained and Constraining Objects for more information).
3. Choose Constrain > Distance and pick the object that is to act as the constraint.
The offset distance value is set for the Distance slider. You can adjust the value here.
4. Deselect the CnsComp button.
5. Translate the constraining object. The constrained object also moves, maintaining the distance you set.
Autodesk Softimage v.7.5