[SOLVED] Lowering contraint response without affecting fall speed

[Glenn]

Hello,

I’m working on making an interactive demo scene in virtual reality, and the focus is mainly to get visually realistic results in real time.
The scene should simulate two or more deformable objects. To create them, I use a SparseGridTopology and a TetrahedronFEMForceField for the deformation force field and a EulerImplicitSolver coupled with a CGLinearSolver for the solvers. Also, each object has its own EulerImplicitSolver and CGLinearSolver.

I started by making a pudding and I think it works fine.

Now, I try to simulate a piece of cheese in the same scene. This object should retrieve its shape very slowly after a contraint relief (more than the pudding). To do that, I use damping in the integration scheme of this object (rayleighStiffness=2.5). This works but it causes the cheese to fall slower than the pudding, which breaks realism.

To counter that, I tried to set a per-object gravity with the ConstantForceField component (to set a stronger gravity for the objects with more damping), but it generates some instabilities that I did not observed when using a “global” gravity force field.

So here is my issue, I am looking for a way to reduce the “shape retrieval speed” (contraint response?) without affecting fall speed. How can this be done ?

I appreciate your advice.

Regards,

Glenn

[Glenn]

Hello,

I just found out about the pasticity properties of the TetraHedronFEMForceField thanks to the example scene TetrahedronFEMForceField_plasticity.scn.
This is close to what I intend to do by “lowering the constraint response” and I think the visual results are satisfactory, so I close this topic.
I was more looking for a way to slow down the shape retrival of the object, but increasing the plasticity is quite similar.

Regards,

Glenn

[Author]

Posts