The MCG Ray to Surface Position Constraint sets an object's position to a location on the surface of one or more meshes as determined by an intersecting ray cast from another object. If desired, you can apply an offset from the surface.
Prepare at least three objects:
Select the object to constrain.
Choose Animation menu > MCG Controllers > MCG Ray to Surface Position Constraint.
Click the surface mesh.
Click the ray origin object.
If desired, you can use Pick Surface to add more mesh surfaces.
Alternatively, you can use Assign Controller on the object's Position track in the Track View or Motion Panel to assign the MCG_rayToSurfacePosition manually, and then use the Pick Surface and Ray Cast Object buttons to specify the appropriate objects.
Click to select additional meshes.
Lists the meshes.
Select an object in the list, and then click this button to remove it.
Click this button to select an object in the scene to serve as the ray origin.
When activated, rays are cast from the ray cast object's center to the centers of the surfaces. Otherwise, a ray is cast along one of the ray cast object's local axes.
The direction of the ray cast from the ray cast object, when Aim at Surface Pivot is off.
Offsets the object's position from the ray intersection. When Use Surface Normal is off, the object is offset along the ray.