Cloth simulation

Cloth simulation

By adding additional constraints to the tension network, cloth simulation becomes possible. For cloth simulation non-linear elasticity is required and springs should be able to aspire any length, instead of just zero.

Also, quad faces in the mesh should be equipped with diagonal anti-collapse springs to prevent face-shearing. Cloth is also subject to external forces so a simple gravity and wind model is required to deform the cloth.

I also added new node constraints:

·	Fixed (Node is locked in space)

·	Line (Node is constrained to an infinite line)

·	Plane (Node is constrained to an infinite plane)

·	Distance (Node is constrained to the surface of a sphere around a given point)

·	Object (Node is constrained to existing geometry such as curves, points, surfaces, BReps and meshes)

For additional information.