2009

Procedures
To fix points in a deformable body in world space:
1 On the Modify panel, click Vertex in the deformable body modifier's
sub-object list.
This lets you select individual vertices in the deformable body.
2 On the Constraints rollout, click Fix Vertices.
A new Constrain To World constraint appears in the constraints list.
3 Ensure the constraint is highlighted in the constraints list.
4 Select the vertices to constrain.
These vertices remain fixed in place during the simulation, while the rest
of the mesh is subject to physical forces and deformation as usual.
5 When you are finished choosing vertices, it's advisable to exit the Vertex
sub-object level. This prevents you accidentally deselecting some of the
constrained vertices before simulating.
6 To change the set of fixed vertices, select the object, access the modifier's
Vertex sub-object level, highlight its Constrain To World constraint in
the list, and then select a different set of vertices.
Keyframing Vertices
reactor modifier (Cloth/Soft Body/Rope) > Constraints rollout
This constraint allows you to make the deformable body's chosen vertices
follow their current animation.
Constraining Deformable Bodies | 4065