Prefer xformers attention and remove flash-attn dependency

app.py

@@ -9,10 +9,10 @@ from typing import Any, Dict, Generator, List, Optional, Tuple
 
 os.environ["OPENCV_IO_ENABLE_OPENEXR"] = "1"
 os.environ["PYTORCH_CUDA_ALLOC_CONF"] = "expandable_segments:True"
-if importlib.util.find_spec("flash_attn") is not None:
-    _attn_backend = "flash_attn"
-elif importlib.util.find_spec("xformers") is not None:
+if importlib.util.find_spec("xformers") is not None:
     _attn_backend = "xformers"
+elif importlib.util.find_spec("flash_attn") is not None:
+    _attn_backend = "flash_attn"
 else:
     _attn_backend = "sdpa"
 os.environ.setdefault("ATTN_BACKEND", _attn_backend)

requirements.txt

@@ -17,9 +17,9 @@ zstandard==0.25.0
 kornia==0.8.2
 timm==1.0.22
 pydantic==2.10.6
+xformers==0.0.27.post2
 gradio_litmodel3d==0.0.1
 git+https://github.com/EasternJournalist/utils3d.git@9a4eb15e4021b67b12c460c7057d642626897ec8
-https://github.com/Dao-AILab/flash-attention/releases/download/v2.7.0.post2/flash_attn-2.7.0.post2+cu12torch2.4cxx11abiFALSE-cp310-cp310-linux_x86_64.whl
 https://github.com/JeffreyXiang/Storages/releases/download/Space_Wheels_251210/cumesh-0.0.1-cp310-cp310-linux_x86_64.whl
 https://github.com/JeffreyXiang/Storages/releases/download/Space_Wheels_251210/flex_gemm-0.0.1-cp310-cp310-linux_x86_64.whl
 https://github.com/JeffreyXiang/Storages/releases/download/Space_Wheels_251210/o_voxel-0.0.1-cp310-cp310-linux_x86_64.whl