FAQ: Simulating cloth, softbodies, ropes and other flexible materials

•  How do I simulate cloth?

Any particle shape mesh can be converted into cloth using a Cloth Bind operator.

•  How do I create ropes/strings/etc?

Ropes and strings can be simulated by converting 3ds Max spline shapes assigned to particles into cloth, or by binding particles birthed on splines together based on their sibling relationships. In fact, any linear chain of bindings can be converted into a rope-like material. Once you’ve created your linear chain of bindings, you can convert it back into a 3ds Max spline with a Spline Paths operator set to “Particle bindings” mode, and by enabling the “weld bindings” setting in the target tySplines object. The resulting 3ds Max splines generated by the tySplines object can be converted into editable geometry with a tySplineMesher modifier.

•  How do I simulate a soft-body that maintains its volume?

Forces exerted on thick softbodies naturally propagate through their volume, as opposed to cloth-like materials whose forces only propagate through their surface.

To simulate volume propagation, you can use a Spawn operator to spawn voxelized particles in the volume of your particle’s shape mesh (prior to converting it to cloth with a Cloth Bind operator), and then use a Particle Bind operator to create a dense network of bindings between those voxelized particles and the surface particles of the cloth itself. As the solver transfers forces through that denser network of bindings, a more natural soft-body look to the cloth will be the result.

A simpler way of converting a cloth to a softbody is to simply enable volume bindings within the Cloth Bind operator’s settings. Using these is merely a way to approximate volumetric forces within a mesh though, and may not yield very realistic results.

•  Why is my cloth extremely stretchy, even though my cloth stiffness settings are very high?

Cloth stiffness is heavily dependent on the number of solver steps used to compute it. The denser the cloth mesh is, the more solver steps will be required to maintain its stiffness. By default, Particle Bind Solver steps are set to a fairly low number, but it’s not unusual for dense cloth to require hundreds of steps to solve correctly. Setting cloth/particle binding solvers to “constrained” mode can help make stretchy cloth somewhat substep independent, but users will still need to adjust solver step count on a per-simulation basis, to achieve the look and feel of the cloth that they want.