[Question] Collision and Instancers

[AntoineRichard]

Question

Hello there,

I'm looking into implementing scenes with many objects per environments, and usually in the USD pipeline, the best way to do this is to use a UsdGeom PointInstancer. I know that the visualization markers are using this mechanism to instantiate many visual objects.

I modified it so that collision properties only could be passed to the prototypes being instanced, but that led to the physics going bonkers in the sim. Is it possible I did something wrong, and can a point instancer work when only collisions are enabled?

I know that an alternative is to use an Sdf Change Block to replicate the behavior of the instancer, but I was hoping there was some other way to do this.

Let me know,

Cheers,

Antoine

[mpgussert]

Heya Antoine!

Can you provide a short clip of the physics "going bonkers"? are things just exploding and flying away? or does it crash with a specific error? I like the idea of using the point instancer with certain meshes for vectorization

[AntoineRichard]

Hi Michael!

Here is a small video:
Dance.webm

I did try some extra things by directly tapping into Fabric through USDRT, but couldn't get it to output to the scene.

[mpgussert]

Is the car is using the point instancer? Or is it the gates? I think the car should be represented as an articulation https://github.com/isaac-sim/IsaacLab/tree/main/source/extensions/omni.isaac.lab/omni/isaac/lab/assets/articulation

[AntoineRichard]

The car is using the "Articulation" class! Only the gates were using the instancer.
I'll see if I can send a small script to reproduce the issue this week!