TexturesAtlas to color each face with different colors

[ne1114]

❓ Questions on how to use PyTorch3D

Hello, I am trying to color a each mesh faces with different colors. I referred to this issue
I have created a face_colors (shape: (F, 4)). And then converted it to appropriate input format for TexturesAtlas using following :

face_tensor = torch.from_numpy(face_colors[:,:3])   # (F, 3)  --> (R,G,B)  and each value is in 0~1
face_tensor = face_tensor[None, :, None, None, :]   # (1, F, 1, 1, 3) 
print(face_tensor.shape)
------
output: torch.Size([1, 9999, 1, 1, 3])

Also as shown below the obj has 9999 faces :

verts, faces, aux = load_obj(obj_filename)
print(faces.verts_idx.shape)
--------
output : torch.Size([9999, 3])

And I used following code to create texture, generate mesh, visualize:

verts, faces, _ = load_obj(obj_filename)
textures = TexturesAtlas(atlas=face_tensor)

mesh = pytorch3d.structures.Meshes(
    verts=[verts],   
    faces=[faces.verts_idx],
    textures=textures
)

fig = plotly_vis.plot_scene(
            {
                'test':
             {
                 'mesh' : mesh
             }
            },
            xaxis={"backgroundcolor": bgcolor},
            yaxis={"backgroundcolor": bgcolor},
            zaxis={"backgroundcolor": bgcolor}
        )
fig.show()

The displayed mesh does not have appropriate color. (Its just one color not related to the face_colors)

Could I ask for advice please?

[bottler]

I think you have set up the mesh correctly in PyTorch3D. So if you render it with the PyTorch3D renderer you should be able to see the colors. You are not seeing them in the plotly visualization because our plotly_vis functionality doesn't look at TexturesAtlas.

It would be a tiny change to the file pytorch3d/vis/plotly_vis.py in PyTorch3D to make it work. I think this version
plotly_vis.py.txt is what you need. Can you try it?

[ne1114]

Thank you so much for quick and kind answer @bottler !!
It worked like a charm!! 🙏
Not sure if there is any history behind it, but I think it'd be useful if plotly_vis support meshes with TexturesAtlas in general!