Menu Cells

Constraint -> Direction

For more information about animating using constraints, see the Constraints section of the Animating User's Guide.

Procedure

2. Choose the Constraint -> Direction command.

3. Pick the object that is to act as a constraint.

The constraining object flashes red. The constrained objects rotate so that their x-axes face the constraining object's centre.

By default, a dotted line appears between the constraining and constrained objects to show the direction of the constraint and to make repositioning simpler. The dotted line can be hidden with the Constraint -> Show Direction command.

4. Translate either type of object as desired.

If the constraining object is translated, the constrained object responds by rotating so that its x-axis remains facing the constraining object. If the constrained objects are translated, they also rotate so their x-axes always face the constraining object.

The rotation of the constrained object around its x-axis can be modified and keyframed by changing its x-axis rotation value (known as the "roll" angle of the object). The Rotation menu cells, however, continue to display the rotation values of the object in global or local coordinates.

Tip:

The Up Vector constraint can be further used on the constrained object to control the "roll" or up direction of the object. See Constraint -> Up Vector for more information.