pytorch3d/pytorch3d/ops/mesh_face_areas_normals.py
Patrick Labatut 3c71ab64cc Remove shebang line when not strictly required
Summary: The shebang line `#!<path to interpreter>` is only required for Python scripts, so remove it on source files for class or function definitions. Additionally explicitly mark as executable the actual Python scripts in the codebase.

Reviewed By: nikhilaravi

Differential Revision: D20095778

fbshipit-source-id: d312599fba485e978a243292f88a180d71e1b55a
2020-03-12 10:39:44 -07:00

64 lines
2.4 KiB
Python

# Copyright (c) Facebook, Inc. and its affiliates. All rights reserved.
import torch
from torch.autograd import Function
from torch.autograd.function import once_differentiable
from pytorch3d import _C
class _MeshFaceAreasNormals(Function):
"""
Torch autograd Function wrapper for face areas & normals C++/CUDA implementations.
"""
@staticmethod
def forward(ctx, verts, faces):
"""
Args:
ctx: Context object used to calculate gradients.
verts: FloatTensor of shape (V, 3), representing the packed
batch verts tensor.
faces: LongTensor of shape (F, 3), representing the packed
batch faces tensor
Returns:
areas: FloatTensor of shape (F,) with the areas of each face
normals: FloatTensor of shape (F,3) with the normals of each face
"""
if not (verts.dim() == 2):
raise ValueError("verts need to be of shape Vx3.")
if not (verts.shape[1] == 3):
raise ValueError("verts need to be of shape Vx3.")
if not (faces.dim() == 2):
raise ValueError("faces need to be of shape Fx3.")
if not (faces.shape[1] == 3):
raise ValueError("faces need to be of shape Fx3.")
if not (faces.dtype == torch.int64):
raise ValueError("faces need to be of type torch.int64.")
# TODO(gkioxari) Change cast to floats once we add support for doubles.
if not (verts.dtype == torch.float32):
verts = verts.float()
ctx.save_for_backward(verts, faces)
areas, normals = _C.face_areas_normals_forward(verts, faces)
return areas, normals
@staticmethod
@once_differentiable
def backward(ctx, grad_areas, grad_normals):
grad_areas = grad_areas.contiguous()
grad_normals = grad_normals.contiguous()
verts, faces = ctx.saved_tensors
# TODO(gkioxari) Change cast to floats once we add support for doubles.
if not (grad_areas.dtype == torch.float32):
grad_areas = grad_areas.float()
if not (grad_normals.dtype == torch.float32):
grad_normals = grad_normals.float()
grad_verts = _C.face_areas_normals_backward(
grad_areas, grad_normals, verts, faces
)
return grad_verts, None
mesh_face_areas_normals = _MeshFaceAreasNormals.apply