Visualizing all possible areas that LIDAR can see with GridMap

[omerfarukadastec]

Visualizing all possible areas that LIDAR can see with GridMap

[jlblancoc]

Hi,
You mean a 2D planar lidar or a 3D lidar?

Your goal is to use one particular lidar scan (fixed data) to ray trace the cells that are visible, right? Or do you want to simulate that lidar data? (I guess it's the former since you're using mvsim but just to confirm)

[omerfarukadastec]

Hi,

I'm trying to do it using 3D lidar. My goal is to color all visible cells using ray tracing or another method according to the pointcloud data received by MVSim. In addition, my goal is to perform this process with multiple lidars, for example, to visualize how many lidars any A cell can be seen by. To give an example, if cell A is seen by 2 different lidars, it is blue; if it sees 3, it is yellow; if it sees 4, it is orange.

At this point, yes, I'm basically trying to do ray tracing, but not through a single lidar scan. For example, when the position of the lidar changes on MVSim, my goal is to be able to see the result again. However, if this is not possible, I can also go through a single scan. I am trying to fully learn the opportunities that MRPT and MVSim offer me in this regard.

[jlblancoc]

I think the best way to go might be using Bonxai's voxel maps, which are integrated in MRPT thru:

• mrpt::maps::CVoxelMap
• mrpt::maps::CVoxelMapRGB

See these examples:

• https://docs.mrpt.org/reference/latest/page_maps_voxelmap_simple.html
• https://docs.mrpt.org/reference/latest/page_maps_voxelmap_from_tum_dataset.html

With that (using the standard insertObservation() API call to insert the 3D point cloud in the voxel map), you should be able to see observed cells by each 3D scan.

Now, counting them and coloring in a custom way is another story. You could create a mrpt::opengl::COctoMapVoxels and manually add the voxels with the color you want for each one, by going over all the bonxai's voxel map cells with the provided visitor methods to which you can pass a C++ lambda.

[omerfarukadastec]

Thanks for the suggestions, I'll try to use the CVoxelMap, CVoxelMapRGB and COctoMapVoxels. I'll update after trying.