Hi,
I’m trying to mimic a power cord using deformable physics with a long cylinder.
I’m using ver 4.2.0.
problem1) I expected that if I can find correct values for Poisson’s ratio, Young’s modulus, then the cylinder would behave like a stiff power cord. But no matter what values are set, it is far from a stiff power cord. Especially Poisson’s ratio is just limited up to 0.4999 in IsaacSim. I think this value is related to stretch.
problem2) And, strangely, deformable cylinder floats slightly in the air instead of sticking to the ground. it falls down at higher position so, look like gravity is working. i dont know how to make it stick just on the ground.
The Poisson’s ratio relates to volume conservation, so not directly to stretch, that should be mainly Young’s modulus.
Our deformable body simulation is not ideal for simulating strings or coords, especially for simulating high bend stiffness. Besides increasing the Youngs, you can try to reduce the time step size or increase the solver iteration count. The resolution will also have a high impact.
The floating you should be able to address by explicitely setting the deformable body’s rest offset and contact offset. The contact offset should be larger than the rest offset. A rest offset of 0 would mean that the deformable will settle exactly on the ground, but collision detection and response will work better with a larger value.
Is there any plan to improve on the performance on thin deformable like strings & coords? I also see a demo of a rope with rigid capsules connected with joints. Are those preferred ways to simulate strings?