Branch trellis update

[iiiCpu]

I had a problem with original Trellis pipeline on Windows 11 (wasted like 6 hours to make it work with no effect). So, I replaced it with Microsoft's one, which now works like charm. For me, I had to launch microsoft/TRELLIS app.py, let it build all it needed to build, copy all microsoft/TRELLIS/trellis contents into ComfyUI-3D-Pack/Gen_3D_Modules/TRELLIS/trellis.

Also, I had to move some mesh postprocess code from trellis.postprocessing_utils into Trellis_Structured_3D_Latents_Models.save_gs as I wanted to get MESH instead of just saved file name.

I also changed Save_3D* nodes to act more like standard Save_Image node: to add index to a file name instead of replacing it. And I also made option to create entire folder, it's useful to save different formats or preview into the same place.

[YanWenKun]

Great job! A small question, maybe trellis_ folder is unnecessary?

[iiiCpu]

A small question, maybe trellis_ folder is unnecessary?

True.

I also made a little clean up in nodes.py.

[YanWenKun]

I just tested this PR and found some files that would be better left unchanged:

1. renderers/gaussian_render.py

   3D-Pack uses diff-gaussian-rasterization from ashawkey, which is incompatible with the version used by the TRELLIS official repo. Other parts of 3D-Pack are using this package as well, so it's better to stay with previous implementation.

2. modules/attention/__init__.py

3. modules/sparse/__init__.py

   3D-Pack uses xformers by default to ensure maximum compatibility. Replacing it with flash_attn would require providing additional options for users to choose from.

4. representations/mesh/flexicubes/examples

   I believe these example files are not needed in this use case.

In addition, modifying the Save 3D Mesh node will break all existing workflows. I suggest creating a new node and including it in a separate pull request.

[iiiCpu]

1. Agreed.

3. I simply replaced Trellis from official Microsoft repo, without much thinking. I don't know much about xformers and flash_attn compatibility. Seems like I have some homework to do.

4. Agreed.

p.s. Gosh, markdown sometimes make me feel so miserable.

[MrForExample]

@iiiCpu Hi, thank you for your contribution, I'll take a closer look later this week In the meantime, can you please remove some unnecessary changes and change it back to xformers, because xformers actually supports flash_attn (Although probably not v3, but in time it should), thanks again in advance :) Have a good day 👍