LiDAR smearing and persistant points in IsaacSim 4.5

Omniverse Isaac Sim
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1

Isaac Sim Version

4.5.0
4.2.0
4.1.0
4.0.0
4.5.0
2023.1.1
2023.1.0-hotfix.1
Other (please specify):

Operating System

Ubuntu 22.04
Ubuntu 20.04
Windows 11
Windows 10
Other (please specify):

GPU Information

  • Model: A5000 ADA
  • Driver Version: 535.183.01

LiDAR smearing and persistent points in IsaacSim 4.5

We are publishing LiDAR points (Hesai XT32) using the LiDAR helper action graph. We have found that when we drop the robot into the scene, there are streaks in the LiDAR points and that anything scanned before hitting the ground remains persistent. This issue does not occur in IsaacSim 4.2.

Here are the streaks.

image
image914Ă—728 57.2 KB

This is the LiDAR action graph.

image
image866Ă—808 76 KB

2 Likes
4

Thanks for bringing this issue up! I have passed it down to our internal team.

Did you enable “publish full scan” in ROS2 RTX Lidar Helper?

5

I see similar issue when simulation Ouster-0 sensor in Isaac Sim 4.5. Video attached below explain this clearly. Please advice on how to mitigate this.
OS: Ubuntu 20.04
GPU: Nvidia A3000 RTX

1 Like
6

yes, publish full scan is enabled

7

@gartsw thanks. Yes this is a known issue. We are currently investigating this.

8

We recently updated the document to include a warning for this

If the lidar rotation rate is slower than the frame rate, the scan buffer will contain returns from multiple frames. If the lidar prim moves between frames, or objects move in the scene, the buffer may contain returns from before the lidar or object(s) moved, causing points to appear as though they are “dragging” behind objects when viewed with the debug draw point cloud writer.

9

In my case, the points are not just dragging, they never disappear. It appears that all points scanned before the robot touches the ground are persistent.

10

Sorry. It might be a different issue. Let me reach out to the internal team

1 Like
11

I’m facing the same issue as described above. Looking forward to a fix or any possible workaround.
Thanks in advance to anyone who can help!