Coustoumized articulation

Hello, I have an application where I need to simulate a floating base system with rigid bodies that do not form a complete tree structure, including closed loops. However, I have derived a model of the system using minimal coordinates and have access to all positions and Jacobians (linear and angular velocities) of centers of mass (COMs) and colliders. Is it possible to implement this in PhysX?

Thanks in advance!

Hi Lars,

Closed loops are supported by PhysX articulations, see here: Articulations — Omniverse Extensions latest documentation

I am not sure I follow about the self-derived system dynamics - would you like to run your own simulation and then drive physics kinematic bodies to get one-way collisions with other elements of the scene?


Hi, I have tried what you proposed but there are some issues regarding closed loop simulations on GPU especially. See this post: Closed articulation simulation problem

I think that by keeping the simulation in minimal coordinates will solve these issues. However I still need to resolve collisions between links and other elements in the scene(i.e the ground plane).

In other words I have derived equations on the form:

Where the only unknowns are the collision forces F_c.

Is this possible to implement in PhysX?

Let me know if anything still is unclear.

Hi Lars,

Yes, we are working on the closed-loop problem, and the GPU side of it in particular. If you can resort to CPU, @gyeoman found that this should work.

PhysX is a simulator that both computes the dynamics, detects any collisions requiring Fc that you state, and then integrates the system.

Is your goal to use your own dynamics, solver, and integrator, and use PhysX just for collision detection?