Point_Cloud Message API

Hi there,

experimenting with a livox lidar on the Jetson Nano.
SDK from Livox inside Websight is running well.
So I want to add more info into the point cloud viewer. For example set the color of the point-cloud to the density of points.
How could this be done? Searched for the message API point_cloud but in the documentation this chapter is empty.

How is the structure of point_cloud?
Also where are the defaults like point size located?

Would be helpful to get some advice.

For whatever reason this isn’t listed in the documentation, but you can find the definition of this proto in isaac/messages/point_cloud.capnp:

@0x8846db30e403e12a;

using import "sample_cloud.capnp".SampleCloudProto;

# A message about a cloud of points.
struct PointCloudProto {
  # The positions of the points
  positions @0:  SampleCloudProto;
  # Optional data about the normals at each point. Must match the number of positions.
  normals @1: SampleCloudProto;
  # The colors at each position. This is optional, but if present must have the same length as `positions`.
  colors @2: SampleCloudProto;
  # The intensity at each position, used for example by LIDAR sensors. This is optional, but if present must
  # have the same length as `positions`.
  intensities @3: SampleCloudProto;
}

the definition for SampleCloudProto is also in the same “messages” directory.

Thanks for the hint!

But i´m not getting any results here…
So in Livox cpp (Lidar) there are proto´s for positions and intensities.
I calculated some color profil from the intensities values like descriped in livox viewer sdk and proto it to colors in the same way like with the intensities.
I define colors_ as SampleCloud1f like intensities. Is that correct?

I always get an error sample cloud channel counts do not match: actual = 1, expected =3
Also error mismatched point and color count in current sample.

Color is put in format 0xFFFFFF like r=255 g=255 b=255…

#############edit Update

there are defintily some topics missing in isaac 2019.2 documentation.
I found the PointCloudProto definition in 2019.1

So Colors are Vector3f, changed it to that and now its running.

Only one point left:

Does anybody know how the color format is? Like (int r, int g, int b)?