Spaces:
Build error
Build error
# Copyright (c) Meta Platforms, Inc. and affiliates. | |
# All rights reserved. | |
# | |
# This source code is licensed under the license found in the | |
# LICENSE file in the root directory of this source tree. | |
from typing import Any, Tuple, Union | |
import mmengine | |
import torch | |
from torch import nn as nn | |
from torch.autograd import Function | |
from ..utils import ext_loader | |
ext_module = ext_loader.load_ext( | |
'_ext', ['roiaware_pool3d_forward', 'roiaware_pool3d_backward']) | |
class RoIAwarePool3d(nn.Module): | |
"""Encode the geometry-specific features of each 3D proposal. | |
Please refer to `PartA2 <https://arxiv.org/pdf/1907.03670.pdf>`_ for more | |
details. | |
Args: | |
out_size (int or tuple): The size of output features. n or | |
[n1, n2, n3]. | |
max_pts_per_voxel (int, optional): The maximum number of points per | |
voxel. Default: 128. | |
mode (str, optional): Pooling method of RoIAware, 'max' or 'avg'. | |
Default: 'max'. | |
""" | |
def __init__(self, | |
out_size: Union[int, tuple], | |
max_pts_per_voxel: int = 128, | |
mode: str = 'max'): | |
super().__init__() | |
self.out_size = out_size | |
self.max_pts_per_voxel = max_pts_per_voxel | |
assert mode in ['max', 'avg'] | |
pool_mapping = {'max': 0, 'avg': 1} | |
self.mode = pool_mapping[mode] | |
def forward(self, rois: torch.Tensor, pts: torch.Tensor, | |
pts_feature: torch.Tensor) -> torch.Tensor: | |
""" | |
Args: | |
rois (torch.Tensor): [N, 7], in LiDAR coordinate, | |
(x, y, z) is the bottom center of rois. | |
pts (torch.Tensor): [npoints, 3], coordinates of input points. | |
pts_feature (torch.Tensor): [npoints, C], features of input points. | |
Returns: | |
torch.Tensor: Pooled features whose shape is | |
[N, out_x, out_y, out_z, C]. | |
""" | |
return RoIAwarePool3dFunction.apply(rois, pts, pts_feature, | |
self.out_size, | |
self.max_pts_per_voxel, self.mode) | |
class RoIAwarePool3dFunction(Function): | |
def forward(ctx: Any, rois: torch.Tensor, pts: torch.Tensor, | |
pts_feature: torch.Tensor, out_size: Union[int, tuple], | |
max_pts_per_voxel: int, mode: int) -> torch.Tensor: | |
""" | |
Args: | |
rois (torch.Tensor): [N, 7], in LiDAR coordinate, | |
(x, y, z) is the bottom center of rois. | |
pts (torch.Tensor): [npoints, 3], coordinates of input points. | |
pts_feature (torch.Tensor): [npoints, C], features of input points. | |
out_size (int or tuple): The size of output features. n or | |
[n1, n2, n3]. | |
max_pts_per_voxel (int): The maximum number of points per voxel. | |
Default: 128. | |
mode (int): Pooling method of RoIAware, 0 (max pool) or 1 (average | |
pool). | |
Returns: | |
torch.Tensor: Pooled features whose shape is | |
[N, out_x, out_y, out_z, C]. | |
""" | |
if isinstance(out_size, int): | |
out_x = out_y = out_z = out_size | |
else: | |
assert len(out_size) == 3 | |
assert mmengine.is_tuple_of(out_size, int) | |
out_x, out_y, out_z = out_size | |
num_rois = rois.shape[0] | |
num_channels = pts_feature.shape[-1] | |
num_pts = pts.shape[0] | |
pooled_features = pts_feature.new_zeros( | |
(num_rois, out_x, out_y, out_z, num_channels)) | |
argmax = pts_feature.new_zeros( | |
(num_rois, out_x, out_y, out_z, num_channels), dtype=torch.int) | |
pts_idx_of_voxels = pts_feature.new_zeros( | |
(num_rois, out_x, out_y, out_z, max_pts_per_voxel), | |
dtype=torch.int) | |
ext_module.roiaware_pool3d_forward( | |
rois, | |
pts, | |
pts_feature, | |
argmax, | |
pts_idx_of_voxels, | |
pooled_features, | |
pool_method=mode) | |
ctx.roiaware_pool3d_for_backward = (pts_idx_of_voxels, argmax, mode, | |
num_pts, num_channels) | |
return pooled_features | |
def backward( | |
ctx: Any, grad_out: torch.Tensor | |
) -> Tuple[None, None, torch.Tensor, None, None, None]: | |
ret = ctx.roiaware_pool3d_for_backward | |
pts_idx_of_voxels, argmax, mode, num_pts, num_channels = ret | |
grad_in = grad_out.new_zeros((num_pts, num_channels)) | |
ext_module.roiaware_pool3d_backward( | |
pts_idx_of_voxels, | |
argmax, | |
grad_out.contiguous(), | |
grad_in, | |
pool_method=mode) | |
return None, None, grad_in, None, None, None | |