Unwanted Lidar Point Smearing in Isaac Sim 4.5.0

Omniverse Isaac Sim
,
1

Isaac Sim Version

  • 4.5.0

Operating System

  • Ubuntu 22.04

GPU Information

  • Model: RTX 3090 Ti
  • Driver Version: 570.124.04

Topic Description

Detailed Description

An issue has been observed with the RTX lidar sensor created via the API in Isaac Sim 4.5.0. The point cloud shows extra points that seem to linger from previous frames. These unwanted points sometimes vanish after 5–10 seconds, but other times they remain, creating a smearing effect.

Steps to Reproduce

  1. Run the debug_draw standalone example in Isaac Sim 4.5.0. (standalone_examples/api/isaacsim.util.debug_draw/rtx_lidar.py )
  2. Quickly move or rotate the lidar sensor.
  3. Notice the point cloud displaying lingering points from earlier frames.

Error Messages

No error messages are shown.

Screenshots or Videos

For additional context, similar issues have been discussed in these threads:

Additional Information

What Has Been Tried

  • Compared behavior between Isaac Sim 4.2 and 4.5.0 using the debug_draw example (the issue appears only in 4.5.0).
  • Tested on a fresh installation of Ubuntu 22.04 with Isaac Sim 4.5.0 and the latest GPU driver (570.124.04).
  • Evaluated different lidar configurations with varying horizontal and vertical resolutions, all with the same outcome.
2 Likes
2

this is a video of the problem. i also tried to publish this points in ROS2 and visualize in RVIZ. same problem. so it is not about the debug_draw extension.

1 Like
5

Thanks @mohammad.ehteshami. Our engineers are currently investigating this issue.

6

I’m also facing this issue. The lidar full scan usage is totally ruined. I’m looking forward to the solution ASAP!

7

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.

8

when viewed with the debug draw point cloud writer.

I’m experiencing the same issue. It’s not just a problem with the debug draw point cloud— even the actual point data is affected. The points have incorrect distances, and these “corrupted” points persist even after new measurements are taken. They don’t disappear right away and sometimes stay in the data for a while, which ends up affecting multiple scans and results.

9

Let me un-resolve this post for now. Our internal team found two issues causing lidar point smearing. One is due to the lidar rotation rate being slower than the frame rate. Our internal team is still trying to root cause and figure out a fix for the other issue.