Basic Question

[LiYan-pro]

Question Description

I installed pytorch3d==0.7.7 on Windows succeed,but when I try to use it I met an intresting problem like this:

If I from pytorch3d import _C it will get wrong, BUT if I 'from pytorch3d.structures import Meshes' first and then from pytorch3d import _C it will be right.

(fp) C:\Users\35964>python
Python 3.9.20 (main, Oct  3 2024, 07:38:01) [MSC v.1929 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import pytorch3d
>>> from pytorch3d import _C
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: DLL load failed while importing _C: 找不到指定的模块。
>>> from pytorch3d.structures import Meshes
>>> from pytorch3d import _C
>>> import sys
>>> sys.path
['', 'E:\\miniconda\\envs\\fp\\python39.zip', 'E:\\miniconda\\envs\\fp\\DLLs', 'E:\\miniconda\\envs\\fp\\lib', 'E:\\miniconda\\envs\\fp', 'E:\\miniconda\\envs\\fp\\lib\\site-packages', 'E:\\miniconda\\envs\\fp\\lib\\site-packages\\nvdiffrast-0.3.3-py3.9.egg', 'E:\\miniconda\\envs\\fp\\lib\\site-packages\\pytorch3d-0.7.7-py3.9-win-amd64.egg', 'E:\\miniconda\\envs\\fp\\lib\\site-packages\\setuptools\\_vendor', 'E:\\miniconda\\envs\\fp\\lib\\site-packages\\win32', 'E:\\miniconda\\envs\\fp\\lib\\site-packages\\win32\\lib', 'E:\\miniconda\\envs\\fp\\lib\\site-packages\\Pythonwin']
>>>

Does anybody know whats wrong with this?

Basic Environment

• Windows 11
• Visual Studio 2019 Developer Command Prompt v16.11.32
• Cuda 11.7
• pytorch 2.0.0
• torchaudio 2.0.0
• torchvision 0.15.0
• CUB 1.17.0

PS: I'd try this method #1013 (comment), it doesn't work.

[bottler]

Yes, this has been discussed on other issues.

1. Note that _C is a private part of pytorch3d. It is not meant to be imported directly by users. The "problem" you report is not a bug.

2. What is going on here is that the binary extension _C will only work if certain binary components of pytorch have already been loaded. The line from pytorch3d import _C will work after import torch has been run. PyTorch3D itself should not have any files which import _C without first importing torch.