2009

The constraint is simulated if it has the correct number of rigid bodies attached,
a specified path shape, and is included in a valid
Constraint Solver on page
3945. When not selected, invalid constraints are red in the viewport.
Procedures
To create a Point-Path constraint:
■ Choose one of the above options, and then click in any viewport to add
the Point-Path constraint.
NOTE The icon’s position has no effect on the constraint’s behavior.
To specify objects and a path for the constraint:
1 Create the constraint and the bodies to constrain.
2 Create a line or curve in the viewport using one of the Shapes tools on
the Create panel.
3 In the constraint’s Properties rollout, click the Child pick button, and
then select the object you want to use as the child object in one of the
viewports.
4 If you do not want to assign a second body to the constraint, turn off
the Parent check box if necessary.
5 If the constraint is to be two-bodied, repeat step 2, using the Parent pick
button to set the parent for the constraint.
6 Use the Path pick button to designate the path.
The constraint icon moves to the designated path. By default, this
constraint type is aligned so that the parent constraint space is aligned
with the path shape's local space, while the child space is aligned with
the child body's local space.
To change the path position and orientation for the bodies:
1 With the constraint selected, open the Modify panel.
2 In the modifier stack open the constraint’s sub-object list.
3 Access the sub-object level corresponding to the object whose constraint
space you want to move: Child Space or Parent Space. If the Point-Path
constraint is single-bodied, Parent Space represents the world position
and rotation of the path.
3996 | Chapter 16 reactor