How can I render a mesh to an image without textures?

[WMCh]

Hi, I tried to render meshes without textures using the codes in the tutorials, but failed because the shader samples the textures of meshes by default.

Traceback (most recent call last):
  File "e:/code/python/Test/render_textured_meshes.py", line 81, in <module>
    images = renderer(mesh)
  File "D:\programs\Anaconda3\lib\site-packages\torch\nn\modules\module.py", line 722, in _call_impl
    result = self.forward(*input, **kwargs)
  File "D:\programs\Anaconda3\lib\site-packages\pytorch3d-0.2.0-py3.8-win-amd64.egg\pytorch3d\renderer\mesh\renderer.py", line 49, in forward
    images = self.shader(fragments, meshes_world, **kwargs)
  File "D:\programs\Anaconda3\lib\site-packages\torch\nn\modules\module.py", line 722, in _call_impl
    result = self.forward(*input, **kwargs)
  File "D:\programs\Anaconda3\lib\site-packages\pytorch3d-0.2.0-py3.8-win-amd64.egg\pytorch3d\renderer\mesh\shader.py", line 108, in forward
    texels = meshes.sample_textures(fragments)
  File "D:\programs\Anaconda3\lib\site-packages\pytorch3d-0.2.0-py3.8-win-amd64.egg\pytorch3d\structures\meshes.py", line 1500, in sample_textures
    raise ValueError("Meshes does not have textures")
ValueError: Meshes does not have textures

In short, how can I simply render a mesh without textures? Or if I modify the source code, will there be any bad effects? Looking forward to you reply, thank you!

[WMCh]

I made some modification to the source code to get the results I wanted.

1. Line 108 in pytorch3d/renderer/mesh/shader.py

texels = None
if meshes.textures is not None:
    texels = meshes.sample_textures(fragments)

2. Line 83 in pytorch3d/renderer/mesh/shading.py

if texels is not None:
    colors = (ambient + diffuse) * texels + specular
    return colors
else:
    colors = ambient + diffuse + specular
    return colors

and the rendered image turned out to be like below:

[gkioxari]

Shaders require textures. Otherwise what are you shading?! This is also shown in the table at the bottom of the notes here

https://github.com/facebookresearch/pytorch3d/blob/master/docs/notes/renderer_getting_started.md

The only shader that doesn't require texture is the SoftSilhouetteShader which returns the silhouette of the object.
If you want to shade your object but it doesn't have textures then you can assign it arbitrary RGB textures, e.g. white (1.0, 1.0, 1.0)

[qiuyu96]

Hi, I tried to render meshes without textures using the codes in the tutorials, but failed because the shader samples the textures of meshes by default.

Traceback (most recent call last):
  File "e:/code/python/Test/render_textured_meshes.py", line 81, in <module>
    images = renderer(mesh)
  File "D:\programs\Anaconda3\lib\site-packages\torch\nn\modules\module.py", line 722, in _call_impl
    result = self.forward(*input, **kwargs)
  File "D:\programs\Anaconda3\lib\site-packages\pytorch3d-0.2.0-py3.8-win-amd64.egg\pytorch3d\renderer\mesh\renderer.py", line 49, in forward
    images = self.shader(fragments, meshes_world, **kwargs)
  File "D:\programs\Anaconda3\lib\site-packages\torch\nn\modules\module.py", line 722, in _call_impl
    result = self.forward(*input, **kwargs)
  File "D:\programs\Anaconda3\lib\site-packages\pytorch3d-0.2.0-py3.8-win-amd64.egg\pytorch3d\renderer\mesh\shader.py", line 108, in forward
    texels = meshes.sample_textures(fragments)
  File "D:\programs\Anaconda3\lib\site-packages\pytorch3d-0.2.0-py3.8-win-amd64.egg\pytorch3d\structures\meshes.py", line 1500, in sample_textures
    raise ValueError("Meshes does not have textures")
ValueError: Meshes does not have textures

In short, how can I simply render a mesh without textures? Or if I modify the source code, will there be any bad effects? Looking forward to you reply, thank you!

I think this url #51 will give you the answer.