The SDF collider is not working properly on the magazine model

Omniverse Isaac Sim
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1

Isaac Sim Version

4.5.0

Operating System

Ubuntu 22.04

GPU Information

  • Model: 4070
  • Driver Version: 570

The SDF mesh is not working properly on the magazine model

Detailed Description

I applied an SDF collider to the magazine model and placed some plates inside (Fig. 1). They fit perfectly (Fig. 2). However, when I run the simulation, the plates jitter, and some of them become misaligned (Fig. 3). Things get even worse then magazine is rotated. I applied primitive colliders to the magazine instead sdf, and it worked perfectly out of the box without needing any physics tweaks. What am I doing wrong here?

Steps to Reproduce

  1. Open and run collected scene: Collected_Magazine.zip (22.4 KB)

Screenshots or Videos

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Figure 1

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Figure 2

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Figure 3

Additional Information

What I’ve Tried

I also experimented with changing various parameters of the SDF colliders and the physics scene:

  • SDF resolution
  • Contact offset (this helped slightly)
  • SDF bits per subgrid
  • Enable SDF remeshing
  • Enabled CCD on both the scene and the PCB magazine
  • Assigned different masses to the plates

I also applied an SDF collider to the plate, but this actually made the situation worse.
I inspected the SDF collider using the Physics Debug tool but couldn’t identify any issues.

3

Hi @booger.bubble1, thank you for your question! I found that enabling CCD on the rigid body, adding a physics scene object and enabling CCD + increasing the timesteps per second to 120 resolved the misalignment issue. I believe this is likely due to the potential issues with discrete time described here: Physics Simulation Fundamentals — Isaac Sim Documentation. Let me know if this resolves your issue!

1 Like
5

Thank you for your answer. But as I wrote earlier I applied primitive colliders to the magazine instead SDF, and it worked perfectly out of the box without needing any physics tweaks. So possibly the problem is with SDF collider itself? Maybe the shape of magazine is not fit for SDF?

6

I wasn’t able to get any other collider configuration working other than the one I described. Could you share more details about the colliders you used that worked on your end?

7

Hello!

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