FEM ConstraintPlaneRotation

Description
Creates a FEM constraint for keeping the nodes in a planar surface in the same plane.

Usage

 * 1) Click on [[Image:FEM_ConstraintPlaneRotation.svg|32px]] or choose → Mechanical Constraints →  from the top menu.
 * 2) Select in the 3D view the object the constraint should be applied to, which can be a face.

Limitations

 * 1) Plane rotation constraint can only be applied to a single planar face.
 * 2) When a plane rotation constraint is applied to the same face as a displacement/fixed constraint, the displacement/fixed constraint takes preference.