Files
OpenPCDet/pcdet/models/backbones_3d/spconv_unet.py
2025-09-21 20:18:55 +08:00

213 lines
8.4 KiB
Python

from functools import partial
import torch
import torch.nn as nn
from ...utils.spconv_utils import replace_feature, spconv
from ...utils import common_utils
from .spconv_backbone import post_act_block
class SparseBasicBlock(spconv.SparseModule):
expansion = 1
def __init__(self, inplanes, planes, stride=1, downsample=None, indice_key=None, norm_fn=None):
super(SparseBasicBlock, self).__init__()
self.conv1 = spconv.SubMConv3d(
inplanes, planes, kernel_size=3, stride=stride, padding=1, bias=False, indice_key=indice_key
)
self.bn1 = norm_fn(planes)
self.relu = nn.ReLU()
self.conv2 = spconv.SubMConv3d(
planes, planes, kernel_size=3, stride=1, padding=1, bias=False, indice_key=indice_key
)
self.bn2 = norm_fn(planes)
self.downsample = downsample
self.stride = stride
def forward(self, x):
identity = x.features
assert x.features.dim() == 2, 'x.features.dim()=%d' % x.features.dim()
out = self.conv1(x)
out = replace_feature(out, self.bn1(out.features))
out = replace_feature(out, self.relu(out.features))
out = self.conv2(out)
out = replace_feature(out, self.bn2(out.features))
if self.downsample is not None:
identity = self.downsample(x)
out = replace_feature(out, out.features + identity)
out = replace_feature(out, self.relu(out.features))
return out
class UNetV2(nn.Module):
"""
Sparse Convolution based UNet for point-wise feature learning.
Reference Paper: https://arxiv.org/abs/1907.03670 (Shaoshuai Shi, et. al)
From Points to Parts: 3D Object Detection from Point Cloud with Part-aware and Part-aggregation Network
"""
def __init__(self, model_cfg, input_channels, grid_size, voxel_size, point_cloud_range, **kwargs):
super().__init__()
self.model_cfg = model_cfg
self.sparse_shape = grid_size[::-1] + [1, 0, 0]
self.voxel_size = voxel_size
self.point_cloud_range = point_cloud_range
norm_fn = partial(nn.BatchNorm1d, eps=1e-3, momentum=0.01)
self.conv_input = spconv.SparseSequential(
spconv.SubMConv3d(input_channels, 16, 3, padding=1, bias=False, indice_key='subm1'),
norm_fn(16),
nn.ReLU(),
)
block = post_act_block
self.conv1 = spconv.SparseSequential(
block(16, 16, 3, norm_fn=norm_fn, padding=1, indice_key='subm1'),
)
self.conv2 = spconv.SparseSequential(
# [1600, 1408, 41] <- [800, 704, 21]
block(16, 32, 3, norm_fn=norm_fn, stride=2, padding=1, indice_key='spconv2', conv_type='spconv'),
block(32, 32, 3, norm_fn=norm_fn, padding=1, indice_key='subm2'),
block(32, 32, 3, norm_fn=norm_fn, padding=1, indice_key='subm2'),
)
self.conv3 = spconv.SparseSequential(
# [800, 704, 21] <- [400, 352, 11]
block(32, 64, 3, norm_fn=norm_fn, stride=2, padding=1, indice_key='spconv3', conv_type='spconv'),
block(64, 64, 3, norm_fn=norm_fn, padding=1, indice_key='subm3'),
block(64, 64, 3, norm_fn=norm_fn, padding=1, indice_key='subm3'),
)
self.conv4 = spconv.SparseSequential(
# [400, 352, 11] <- [200, 176, 5]
block(64, 64, 3, norm_fn=norm_fn, stride=2, padding=(0, 1, 1), indice_key='spconv4', conv_type='spconv'),
block(64, 64, 3, norm_fn=norm_fn, padding=1, indice_key='subm4'),
block(64, 64, 3, norm_fn=norm_fn, padding=1, indice_key='subm4'),
)
if self.model_cfg.get('RETURN_ENCODED_TENSOR', True):
last_pad = self.model_cfg.get('last_pad', 0)
self.conv_out = spconv.SparseSequential(
# [200, 150, 5] -> [200, 150, 2]
spconv.SparseConv3d(64, 128, (3, 1, 1), stride=(2, 1, 1), padding=last_pad,
bias=False, indice_key='spconv_down2'),
norm_fn(128),
nn.ReLU(),
)
else:
self.conv_out = None
# decoder
# [400, 352, 11] <- [200, 176, 5]
self.conv_up_t4 = SparseBasicBlock(64, 64, indice_key='subm4', norm_fn=norm_fn)
self.conv_up_m4 = block(128, 64, 3, norm_fn=norm_fn, padding=1, indice_key='subm4')
self.inv_conv4 = block(64, 64, 3, norm_fn=norm_fn, indice_key='spconv4', conv_type='inverseconv')
# [800, 704, 21] <- [400, 352, 11]
self.conv_up_t3 = SparseBasicBlock(64, 64, indice_key='subm3', norm_fn=norm_fn)
self.conv_up_m3 = block(128, 64, 3, norm_fn=norm_fn, padding=1, indice_key='subm3')
self.inv_conv3 = block(64, 32, 3, norm_fn=norm_fn, indice_key='spconv3', conv_type='inverseconv')
# [1600, 1408, 41] <- [800, 704, 21]
self.conv_up_t2 = SparseBasicBlock(32, 32, indice_key='subm2', norm_fn=norm_fn)
self.conv_up_m2 = block(64, 32, 3, norm_fn=norm_fn, indice_key='subm2')
self.inv_conv2 = block(32, 16, 3, norm_fn=norm_fn, indice_key='spconv2', conv_type='inverseconv')
# [1600, 1408, 41] <- [1600, 1408, 41]
self.conv_up_t1 = SparseBasicBlock(16, 16, indice_key='subm1', norm_fn=norm_fn)
self.conv_up_m1 = block(32, 16, 3, norm_fn=norm_fn, indice_key='subm1')
self.conv5 = spconv.SparseSequential(
block(16, 16, 3, norm_fn=norm_fn, padding=1, indice_key='subm1')
)
self.num_point_features = 16
def UR_block_forward(self, x_lateral, x_bottom, conv_t, conv_m, conv_inv):
x_trans = conv_t(x_lateral)
x = x_trans
x = replace_feature(x, torch.cat((x_bottom.features, x_trans.features), dim=1))
x_m = conv_m(x)
x = self.channel_reduction(x, x_m.features.shape[1])
x = replace_feature(x, x_m.features + x.features)
x = conv_inv(x)
return x
@staticmethod
def channel_reduction(x, out_channels):
"""
Args:
x: x.features (N, C1)
out_channels: C2
Returns:
"""
features = x.features
n, in_channels = features.shape
assert (in_channels % out_channels == 0) and (in_channels >= out_channels)
x = replace_feature(x, features.view(n, out_channels, -1).sum(dim=2))
return x
def forward(self, batch_dict):
"""
Args:
batch_dict:
batch_size: int
vfe_features: (num_voxels, C)
voxel_coords: (num_voxels, 4), [batch_idx, z_idx, y_idx, x_idx]
Returns:
batch_dict:
encoded_spconv_tensor: sparse tensor
point_features: (N, C)
"""
voxel_features, voxel_coords = batch_dict['voxel_features'], batch_dict['voxel_coords']
batch_size = batch_dict['batch_size']
input_sp_tensor = spconv.SparseConvTensor(
features=voxel_features,
indices=voxel_coords.int(),
spatial_shape=self.sparse_shape,
batch_size=batch_size
)
x = self.conv_input(input_sp_tensor)
x_conv1 = self.conv1(x)
x_conv2 = self.conv2(x_conv1)
x_conv3 = self.conv3(x_conv2)
x_conv4 = self.conv4(x_conv3)
if self.conv_out is not None:
# for detection head
# [200, 176, 5] -> [200, 176, 2]
out = self.conv_out(x_conv4)
batch_dict['encoded_spconv_tensor'] = out
batch_dict['encoded_spconv_tensor_stride'] = 8
# for segmentation head
# [400, 352, 11] <- [200, 176, 5]
x_up4 = self.UR_block_forward(x_conv4, x_conv4, self.conv_up_t4, self.conv_up_m4, self.inv_conv4)
# [800, 704, 21] <- [400, 352, 11]
x_up3 = self.UR_block_forward(x_conv3, x_up4, self.conv_up_t3, self.conv_up_m3, self.inv_conv3)
# [1600, 1408, 41] <- [800, 704, 21]
x_up2 = self.UR_block_forward(x_conv2, x_up3, self.conv_up_t2, self.conv_up_m2, self.inv_conv2)
# [1600, 1408, 41] <- [1600, 1408, 41]
x_up1 = self.UR_block_forward(x_conv1, x_up2, self.conv_up_t1, self.conv_up_m1, self.conv5)
batch_dict['point_features'] = x_up1.features
point_coords = common_utils.get_voxel_centers(
x_up1.indices[:, 1:], downsample_times=1, voxel_size=self.voxel_size,
point_cloud_range=self.point_cloud_range
)
batch_dict['point_coords'] = torch.cat((x_up1.indices[:, 0:1].float(), point_coords), dim=1)
return batch_dict