Constructed mesh is black

[DevAB-Git]

Hi,
I'm trying to create a mesh for a simple environment (i.e. playpen, ROS noetic and Gazebo). I used 10 pcd files (recorded using HDL-32E lidar) to create the mesh environment by using the following steps:

1- Remove radius outliers (nb_points=10, radius=0.8) from pcd files and save as ply files

2- Register ply files using point-to-plane ICP and pose graph optimization

3- Combine the ply files. Apparently, the combined cloud looks good (see combined_plys.png).

4- Reconstruct the mesh environment using poisson reconstruction (depth=14). The resultant mesh file shows a black rectangle only (see front.png). The flipped side show a kind of playpen environment but in bad look (see flipped.png). It is observed that the construction process generate a warning "Extract bad average roots: 21".

Could you guys suggest how to fix this issue? Thanks in advance

Combined pointcloud

Mesh Front

Mesh Flipped

[DevAB-Git]

I did some R&D and observed that normals play a critical role in mesh reconstruction. I created the normals using cloudcompare and then set their orientation using orient_normals_to_align_with_direction. The registered and combined cloud now have normals, apparently aligned (see pic normals_front and normals_back). Consequently, there is some improvement in the flipped mesh but still the front side is a black rectangle. Any help/hint is much appreciated.

normals_front

normals_back

Mesh Flipped

[Mollylulu]

@DevAB-Git hi~ I met the same issue as yours. Were you able to find a solution? If you did, I would greatly appreciate it if you could share your solution. Thank you!

[EwingKang]

Did you call SetVertexColors()? If not, you might want to do so. I can display open3d::t::geometry::TriangleMesh color properly with that API. It wont be generated automatically as far as I'm aware.
API:
https://www.open3d.org/docs/latest/cpp_api/classopen3d_1_1t_1_1geometry_1_1_triangle_mesh.html