Bug: Physx ParticleSet does not simulate

As apart of doing some R&D on creating Blender to Omniverse workflow tutorials, I stumbled upon what I believe is a bug in Physx PBD Particles and the Add → Particle Set menu option.

What I believe is happening is, the Add->Particle Set menu option is not creating a Velocities array that is the length Points array, this results in the Points not simulating.

To reproduce, simply export some Points from a DCC (Houdini for example), then bring them into an OV App and attempt the Add->Particle Set menu option. Inspect the Points, and you’ll notice that the Velocities parameter is null (not initialized) and that the Points do not simulate.

Now, if you go back to Houdini and add a ‘v’ vector3 to those Points, import them into Solaris (this will create the Velocities array), and then export those Points to USD again, and now invoke Add->ParticleSet, the Points will now simulate as expected.

My point is, it (ParticleSet) did not to behave this way in prior versions of Omniverse - at least I dont recall having to do this extra step of ensuring the imported Points had a valued Velocities array - more specifically, the OV Documentation dont mention this critical piece of data being required when using ParticleSet.

Thanks @daryl.dunlap.ohio. I’ll bring this to the attention of the devs.

Thanks for reporting this! It’s clearly a bug and I filed a ticket.