Summary:
Enables building pytorch3d's `_C` extension against a ROCm-built PyTorch and running the test suite on AMD GPUs, including the pulsar subrenderer. Verified on AMD Instinct MI250X (gfx90a, warpSize=64), HIP 7.2, PyTorch 2.13.
## Mechanics
`torch.utils.cpp_extension.BuildExtension` auto-hipifies `.cu` sources of a `CUDAExtension` against a HIP-built torch (`cuda_runtime.h → hip/hip_runtime.h`, `cub:: → hipcub::`, `cudaStream_t → hipStream_t`, etc.), so most of the lift is build-system glue and a small number of CUDA intrinsics that don't have HIP equivalents.
- `setup.py`: detect ROCm via `torch.version.hip is not None`; treat `ROCM_HOME` as the GPU-toolkit-root analogue of `CUDA_HOME` (without this, `CUDA_HOME is None` silently demoted the build to a CPU-only `CppExtension`); skip `CUB_HOME`, CUDA-13 visibility flags, and `-ccbin=` on ROCm.
- `pytorch3d/csrc/pulsar/gpu/commands.h`: CUDA's `_rn`-suffixed FP rounding intrinsics (`__fadd_rn`, `__fdiv_rn`, `__fsqrt_rn`, `__fmaf_rn`, `__frcp_rn`) and `__saturatef` have no HIP equivalents — AMD's GPU ISA has no instruction-level rounding-mode override, so they expand to plain operators / `sqrtf` / `fmaf` / `1.0f/x` / `fmaxf(0,fminf(1,x))` on the `USE_ROCM` arm, which are rounding-mode-equivalent (both round-to-nearest-even). The HIP compiler may fuse `a+b*c` into a single-rounding FMA where CUDA's `_rn` would have prevented it; if FMA-fusion drift ever becomes a numerical issue, add `-ffp-contract=off` to pulsar's HIPCC flags. `__powf` is replaced with `powf`. `atomicAdd_block` has no HIP function-name equivalent — the semantic equivalent is `__hip_atomic_fetch_add(ptr, val, __ATOMIC_RELAXED, __HIP_MEMORY_SCOPE_WORKGROUP)` (plain HIP `atomicAdd` is device-scope, strictly stronger than block-scope and forces L2-coherent atomics).
- `tests/test_point_mesh_distance.py`: loosen `grad_faces` tolerance in `test_point_face_distance` from `5e-7` to `5e-6` to match the sibling `test_face_point_distance`. The backward kernel uses `atomicAdd` and calls `alertNotDeterministic`; FP add order varies by wavefront width.
- The X_t / camera-R/T equality checks in `test_points_alignment.py` and `test_cameras_alignment.py` are now skipped when `n_points <= dim` (resp. `batch_size <= 3` for camera-center alignment in 3D). Mean-centering renders the SVD rank-deficient in those cases, so the rotation around the degenerate axis is non-unique and different BLAS implementations (rocBLAS RDNA vs CDNA, cuBLAS) pick different valid null-space directions. The center-alignment check still runs and verifies the well-defined part of the transformation.
Pull Request resolved: https://github.com/facebookresearch/pytorch3d/pull/2039
Test Plan:
All GPU tests pass on both AMD Instinct MI250X (gfx90a, wave64, HIP 7.2) and AMD Radeon Pro W7800 (gfx1100, wave32, HIP 7.2.53211, torch 2.13.0a0).
| Module | Result |
|---|---|
| knn, ball_query, sample_farthest_points, face_areas_normals | all pass |
| rasterize_points, rasterize_meshes, chamfer, packed_to_padded | all pass |
| interpolate_face_attributes, blending, compositing, sample_pdf, mesh_normal_consistency | all pass |
| point_mesh_distance | 9/9 pass (with tolerance fix in this PR) |
| pulsar/test_forward, test_channels, test_depth, test_hands, test_ortho, test_small_spheres | 10 passed (FB_TEST=1) |
| test_render_points pulsar tests, test_camera_conversions::test_pulsar_conversion | 3 passed |
| points_to_volumes, iou_box3d, marching_cubes | 20 failures, all env-only |
The 20 env-only failures are `torch.inverse()` on CPU tensors in test reference paths; this verification host's PyTorch was built with `USE_LAPACK: 0` (only `mkl-static` `.a` archives in the conda env; PyTorch's `FindBLAS` looks for `libmkl_intel_lp64.so`). Unrelated to the port — re-verifying with a LAPACK-linked PyTorch is left to upstream.
Reviewed By: MichaelRamamonjisoa
Differential Revision: D106825690
Pulled By: bottler
fbshipit-source-id: f7a9b6028e6fb555f3b8c0f9792e88b818327166
Summary: Move from isort to usort now that usort supports sorting within lines.
Reviewed By: patricklabatut
Differential Revision: D35893280
fbshipit-source-id: 621c1cd285199d785408504430ee0bdf8683b21e
Summary:
Github action to close issues/PRs that are not labelled with "enhancement" or "how-to" if they have not had any activity in 30 days.
Pull Request resolved: https://github.com/facebookresearch/pytorch3d/pull/721
Reviewed By: bottler
Differential Revision: D29309817
Pulled By: nikhilaravi
fbshipit-source-id: 039f6d4f29e9d04c01f59d145317a34ad75026a5
Summary: Added images for four tutorials to add to the README.
Reviewed By: gkioxari
Differential Revision: D24411993
fbshipit-source-id: 5f0b2256efb156b5956013c26b8ddb1631bd1c46
Summary: Use a consistent case for PyTorch3D (matching the logo...): replace all occurrences of PyTorch3d with PyTorch3D across the codebase (including documentation and notebooks)
Reviewed By: wanyenlo, gkioxari
Differential Revision: D20427546
fbshipit-source-id: 8c7697f51434c51e99b7fe271935932c72a1d9b9
