Can we crop the mesh generated through NVBLOX?

Robotics & Edge Computing Robotics - Isaac Isaac ROS
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nvblox
nvblox1223Ă—664 344 KB

Please refer to the image attached. can we crop the mesh generated through nvblox? I want 3D mesh of particular height and of particular distance only. Is there any parameter available for that so we can generate a 3D scene of certain height and of certain distance from the camera only? I am using realsense D435i camera for that. If no then is there any other way to do that?

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Hi @Vatsal_28

Isaac ROS nvblox does not currently support mesh cropping, but I have noted your request for a future release.

About mesh building, there are some parameters to control the max height that can be helpful:

ROS Parameter Type Default Description
esdf_slice_height float 1.0 The output slice height for the distance slice and ESDF pointcloud. Does not need to be within min and max height below. In units of meters.
esdf_2d_min_height float 0.0 The minimum height, in meters, to consider obstacles part of the 2D ESDF slice.
esdf_2d_max_height float 1.0 The maximum height, in meters, to consider obstacles part of the 2D ESDF slice.

I’m also forwarding your question to engineering to find other parameters that can help you tune your map building more effectively.

Best,
Raffaello

1 Like
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Other parameters can be helpful

  • The parameter projective_integrator_max_integration_distance_m acts as an upper limit for the distance to the camera. This value applies in all directions; we do not treat height differently here.
  • When visualizing through rviz or foxglove, the parameter mesh_streamer_exclusion_height_m can limit the height.

You can also use third-party tools like Meshlab or Blender to clean up the mesh.

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Okay, Thank you. @Raffaello

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Hi @Raffaello ,

Just to clarify, are these three height values measured from the ground (can Nvblox detect the ground?) or from the height of the camera? Also, I want to make sure esdf_slice_height is for visualization in rviz while esdf_2d_min_height and esdf_2d_max_height is for real obstacle detection right?

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Hi @AustinCTH

The esdf parameters are related to the algorithm and not for only the visualization.

Best,
Raffaello

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Hi @Raffaello,

Are the esdf_slice_height, esdf_2d_min_height, esdf_2d_max_height all from measured from the ground (i.e. where the robot “starts”) or from where the camera currently is?

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Hi @rngujarathi

They should be related to the base_link.

I’m asking the engineering for a double check.

Best,
Raffaello

1 Like
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Hi @rngujarathi and @Raffaello

They are not related to base_link, but i’ve made a fork where it follows base_link instead of beeing static