Add modules before mg_head in centerpoint (#46)

* Add centerpoint_rpn and scn, change pillar encoder and voxel_encoder

* Move test_voxel_encoders.

* Change names, add docstring.

* Reconstruct centerpoint_rpn.

* Add centerpoint_rpn.

* Change SECONDFPN, delete centerpoint_fpn

* Remove SparseBasicBlock.

* Change SpMiddleResNetFHD to SparseEncoder.

* Finish SparseEncoder unittest.

* Change test_hard_simple_VFE.

* Change option, add legacy.

* Change docstring, change legacy.

* Fix legacy bug.

* Change unittest, change docstring.

* Change docstring.

mmdet3d/models/middle_encoders/sparse_encoder.py

 from torch import nn as nn
 
-from mmdet3d.ops import make_sparse_convmodule
+from mmdet3d.ops import SparseBasicBlock, make_sparse_convmodule
 from mmdet3d.ops import spconv as spconv
 from ..registry import MIDDLE_ENCODERS
 
@@ -12,12 +12,19 @@ class SparseEncoder(nn.Module):
     Args:
         in_channels (int): The number of input channels.
         sparse_shape (list[int]): The sparse shape of input tensor.
-        norm_cfg (dict): Config of normalization layer.
+        order (list[str]): Order of conv module. Defaults to ('conv',
+            'norm', 'act').
+        norm_cfg (dict): Config of normalization layer. Defaults to
+            dict(type='BN1d', eps=1e-3, momentum=0.01).
         base_channels (int): Out channels for conv_input layer.
+            Defaults to 16.
         output_channels (int): Out channels for conv_out layer.
+            Defaults to 128.
         encoder_channels (tuple[tuple[int]]):
             Convolutional channels of each encode block.
         encoder_paddings (tuple[tuple[int]]): Paddings of each encode block.
+            Defaults to ((16, ), (32, 32, 32), (64, 64, 64), (64, 64, 64)).
+        block_type (str): Type of the block to use. Defaults to 'conv_module'.
     """
 
     def __init__(self,
@@ -30,8 +37,10 @@ class SparseEncoder(nn.Module):
                  encoder_channels=((16, ), (32, 32, 32), (64, 64, 64), (64, 64,
                                                                         64)),
                  encoder_paddings=((1, ), (1, 1, 1), (1, 1, 1), ((0, 1, 1), 1,
-                                                                 1))):
+                                                                 1)),
+                 block_type='conv_module'):
         super().__init__()
+        assert block_type in ['conv_module', 'basicblock']
         self.sparse_shape = sparse_shape
         self.in_channels = in_channels
         self.order = order
@@ -66,7 +75,10 @@ class SparseEncoder(nn.Module):
                 conv_type='SubMConv3d')
 
         encoder_out_channels = self.make_encoder_layers(
-            make_sparse_convmodule, norm_cfg, self.base_channels)
+            make_sparse_convmodule,
+            norm_cfg,
+            self.base_channels,
+            block_type=block_type)
 
         self.conv_out = make_sparse_convmodule(
             encoder_out_channels,
@@ -111,17 +123,27 @@ class SparseEncoder(nn.Module):
 
         return spatial_features
 
-    def make_encoder_layers(self, make_block, norm_cfg, in_channels):
+    def make_encoder_layers(self,
+                            make_block,
+                            norm_cfg,
+                            in_channels,
+                            block_type='conv_module',
+                            conv_cfg=dict(type='SubMConv3d')):
         """make encoder layers using sparse convs.
 
         Args:
             make_block (method): A bounded function to build blocks.
             norm_cfg (dict[str]): Config of normalization layer.
             in_channels (int): The number of encoder input channels.
+            block_type (str): Type of the block to use. Defaults to
+                'conv_module'.
+            conv_cfg (dict): Config of conv layer. Defaults to
+                dict(type='SubMConv3d').
 
         Returns:
             int: The number of encoder output channels.
         """
+        assert block_type in ['conv_module', 'basicblock']
         self.encoder_layers = spconv.SparseSequential()
 
         for i, blocks in enumerate(self.encoder_channels):
@@ -130,7 +152,7 @@ class SparseEncoder(nn.Module):
                 padding = tuple(self.encoder_paddings[i])[j]
                 # each stage started with a spconv layer
                 # except the first stage
-                if i != 0 and j == 0:
+                if i != 0 and j == 0 and block_type == 'conv_module':
                     blocks_list.append(
                         make_block(
                             in_channels,
@@ -141,6 +163,26 @@ class SparseEncoder(nn.Module):
                             padding=padding,
                             indice_key=f'spconv{i + 1}',
                             conv_type='SparseConv3d'))
+                elif block_type == 'basicblock':
+                    if j == len(blocks) - 1 and i != len(
+                            self.encoder_channels) - 1:
+                        blocks_list.append(
+                            make_block(
+                                in_channels,
+                                out_channels,
+                                3,
+                                norm_cfg=norm_cfg,
+                                stride=2,
+                                padding=padding,
+                                indice_key=f'spconv{i + 1}',
+                                conv_type='SparseConv3d'))
+                    else:
+                        blocks_list.append(
+                            SparseBasicBlock(
+                                out_channels,
+                                out_channels,
+                                norm_cfg=norm_cfg,
+                                conv_cfg=conv_cfg))
                 else:
                     blocks_list.append(
                         make_block(

mmdet3d/models/necks/second_fpn.py

+import numpy as np
 import torch
-from mmcv.cnn import (build_norm_layer, build_upsample_layer, constant_init,
-                      is_norm, kaiming_init)
+from mmcv.cnn import (build_conv_layer, build_norm_layer, build_upsample_layer,
+                      constant_init, is_norm, kaiming_init)
 from torch import nn as nn
 
 from mmdet.models import NECKS
@@ -11,11 +12,14 @@ class SECONDFPN(nn.Module):
     """FPN used in SECOND/PointPillars/PartA2/MVXNet.
 
     Args:
-        in_channels (list[int]): Input channels of multi-scale feature maps
-        out_channels (list[int]): Output channels of feature maps
-        upsample_strides (list[int]): Strides used to upsample the feature maps
-        norm_cfg (dict): Config dict of normalization layers
-        upsample_cfg (dict): Config dict of upsample layers
+        in_channels (list[int]): Input channels of multi-scale feature maps.
+        out_channels (list[int]): Output channels of feature maps.
+        upsample_strides (list[int]): Strides used to upsample the
+            feature maps.
+        norm_cfg (dict): Config dict of normalization layers.
+        upsample_cfg (dict): Config dict of upsample layers.
+        conv_cfg (dict): Config dict of conv layers.
+        use_conv_for_no_stride (bool): Whether to use conv when stride is 1.
     """
 
     def __init__(self,
@@ -23,7 +27,9 @@ class SECONDFPN(nn.Module):
                  out_channels=[256, 256, 256],
                  upsample_strides=[1, 2, 4],
                  norm_cfg=dict(type='BN', eps=1e-3, momentum=0.01),
-                 upsample_cfg=dict(type='deconv', bias=False)):
+                 upsample_cfg=dict(type='deconv', bias=False),
+                 conv_cfg=dict(type='Conv2d', bias=False),
+                 use_conv_for_no_stride=False):
         # if for GroupNorm,
         # cfg is dict(type='GN', num_groups=num_groups, eps=1e-3, affine=True)
         super(SECONDFPN, self).__init__()
@@ -33,12 +39,23 @@ class SECONDFPN(nn.Module):
 
         deblocks = []
         for i, out_channel in enumerate(out_channels):
+            stride = upsample_strides[i]
+            if stride > 1 or (stride == 1 and not use_conv_for_no_stride):
                 upsample_layer = build_upsample_layer(
                     upsample_cfg,
                     in_channels=in_channels[i],
                     out_channels=out_channel,
                     kernel_size=upsample_strides[i],
                     stride=upsample_strides[i])
+            else:
+                stride = np.round(1 / stride).astype(np.int64)
+                upsample_layer = build_conv_layer(
+                    conv_cfg,
+                    in_channels=in_channels[i],
+                    out_channels=out_channel,
+                    kernel_size=stride,
+                    stride=stride)
+
             deblock = nn.Sequential(upsample_layer,
                                     build_norm_layer(norm_cfg, out_channel)[1],
                                     nn.ReLU(inplace=True))

mmdet3d/models/voxel_encoders/pillar_encoder.py

@@ -31,6 +31,8 @@ class PillarFeatureNet(nn.Module):
             Defaults to dict(type='BN1d', eps=1e-3, momentum=0.01).
         mode (str, optional): The mode to gather point features. Options are
             'max' or 'avg'. Defaults to 'max'.
+        legacy (bool): Whether to use the new behavior or
+            the original behavior. Defaults to True.
     """
 
     def __init__(self,
@@ -42,9 +44,11 @@ class PillarFeatureNet(nn.Module):
                  voxel_size=(0.2, 0.2, 4),
                  point_cloud_range=(0, -40, -3, 70.4, 40, 1),
                  norm_cfg=dict(type='BN1d', eps=1e-3, momentum=0.01),
-                 mode='max'):
+                 mode='max',
+                 legacy=True):
         super(PillarFeatureNet, self).__init__()
         assert len(feat_channels) > 0
+        self.legacy = legacy
         if with_cluster_center:
             in_channels += 3
         if with_voxel_center:
@@ -89,7 +93,7 @@ class PillarFeatureNet(nn.Module):
             features (torch.Tensor): Point features or raw points in shape
                 (N, M, C).
             num_points (torch.Tensor): Number of points in each pillar.
-            coors (torch.Tensor): Coordinates of each voxel
+            coors (torch.Tensor): Coordinates of each voxel.
 
         Returns:
             torch.Tensor: Features of pillars.
@@ -104,7 +108,17 @@ class PillarFeatureNet(nn.Module):
             features_ls.append(f_cluster)
 
         # Find distance of x, y, and z from pillar center
+        dtype = features.dtype
         if self._with_voxel_center:
+            if not self.legacy:
+                f_center = torch.zeros_like(features[:, :, :2])
+                f_center[:, :, 0] = features[:, :, 0] - (
+                    coors[:, 3].to(dtype).unsqueeze(1) * self.vx +
+                    self.x_offset)
+                f_center[:, :, 1] = features[:, :, 1] - (
+                    coors[:, 2].to(dtype).unsqueeze(1) * self.vy +
+                    self.y_offset)
+            else:
                 f_center = features[:, :, :2]
                 f_center[:, :, 0] = f_center[:, :, 0] - (
                     coors[:, 3].type_as(features).unsqueeze(1) * self.vx +

mmdet3d/models/voxel_encoders/voxel_encoder.py

@@ -13,10 +13,14 @@ class HardSimpleVFE(nn.Module):
     """Simple voxel feature encoder used in SECOND.
 
     It simply averages the values of points in a voxel.
+
+    Args:
+        num_features (int): Number of features to use. Default: 4.
     """
 
-    def __init__(self):
+    def __init__(self, num_features=4):
         super(HardSimpleVFE, self).__init__()
+        self.num_features = num_features
 
     def forward(self, features, num_points, coors):
         """Forward function.
@@ -32,7 +36,7 @@ class HardSimpleVFE(nn.Module):
         Returns:
             torch.Tensor: Mean of points inside each voxel in shape (N, 3(4))
         """
-        points_mean = features[:, :, :4].sum(
+        points_mean = features[:, :, :self.num_features].sum(
             dim=1, keepdim=False) / num_points.type_as(features).view(-1, 1)
         return points_mean.contiguous()
 

tests/test_middle_encoders.py

+import pytest
+import torch
+
+from mmdet3d.models.builder import build_middle_encoder
+
+
+def test_sparse_encoder():
+    if not torch.cuda.is_available():
+        pytest.skip('test requires GPU and torch+cuda')
+    sparse_encoder_cfg = dict(
+        type='SparseEncoder',
+        in_channels=5,
+        sparse_shape=[40, 1024, 1024],
+        order=('conv', 'norm', 'act'),
+        encoder_channels=((16, 16, 32), (32, 32, 64), (64, 64, 128), (128,
+                                                                      128)),
+        encoder_paddings=((1, 1, 1), (1, 1, 1), (1, 1, 1), (1, 1, 1), (1, 1,
+                                                                       1)),
+        option='basicblock')
+
+    sparse_encoder = build_middle_encoder(sparse_encoder_cfg).cuda()
+    voxel_features = torch.rand([207842, 5]).cuda()
+    coors = torch.randint(0, 4, [207842, 4]).cuda()
+
+    ret = sparse_encoder(voxel_features, coors, 4)
+    assert ret.shape == torch.Size([4, 256, 128, 128])

tests/test_necks.py

+import torch
+
+from mmdet3d.models.builder import build_backbone, build_neck
+
+
+def test_centerpoint_fpn():
+
+    second_cfg = dict(
+        type='SECOND',
+        in_channels=64,
+        out_channels=[64, 128, 256],
+        layer_nums=[3, 5, 5],
+        layer_strides=[2, 2, 2],
+        norm_cfg=dict(type='BN', eps=1e-3, momentum=0.01),
+        conv_cfg=dict(type='Conv2d', bias=False))
+
+    second = build_backbone(second_cfg)
+
+    # centerpoint usage of fpn
+    centerpoint_fpn_cfg = dict(
+        type='SECONDFPN',
+        in_channels=[64, 128, 256],
+        out_channels=[128, 128, 128],
+        upsample_strides=[0.5, 1, 2],
+        norm_cfg=dict(type='BN', eps=1e-3, momentum=0.01),
+        upsample_cfg=dict(type='deconv', bias=False),
+        use_conv_for_no_stride=True)
+
+    # original usage of fpn
+    fpn_cfg = dict(
+        type='SECONDFPN',
+        in_channels=[64, 128, 256],
+        upsample_strides=[1, 2, 4],
+        out_channels=[128, 128, 128])
+
+    second_fpn = build_neck(fpn_cfg)
+
+    centerpoint_second_fpn = build_neck(centerpoint_fpn_cfg)
+
+    input = torch.rand([4, 64, 512, 512])
+    sec_output = second(input)
+    centerpoint_output = centerpoint_second_fpn(sec_output)
+    second_output = second_fpn(sec_output)
+    assert centerpoint_output[0].shape == torch.Size([4, 384, 128, 128])
+    assert second_output[0].shape == torch.Size([4, 384, 256, 256])

tests/test_voxel_encoders.py

+import torch
+
+from mmdet3d.models.builder import build_voxel_encoder
+
+
+def test_pillar_feature_net():
+    pillar_feature_net_cfg = dict(
+        type='PillarFeatureNet',
+        in_channels=5,
+        feat_channels=[64],
+        with_distance=False,
+        voxel_size=(0.2, 0.2, 8),
+        point_cloud_range=(-51.2, -51.2, -5.0, 51.2, 51.2, 3.0),
+        norm_cfg=dict(type='BN1d', eps=1e-3, momentum=0.01))
+
+    pillar_feature_net = build_voxel_encoder(pillar_feature_net_cfg)
+
+    features = torch.rand([97297, 20, 5])
+    num_voxels = torch.randint(1, 100, [97297])
+    coors = torch.randint(0, 100, [97297, 4])
+
+    features = pillar_feature_net(features, num_voxels, coors)
+    assert features.shape == torch.Size([97297, 64])
+
+
+def test_hard_simple_VFE():
+    hard_simple_VFE_cfg = dict(type='HardSimpleVFE', num_features=5)
+    hard_simple_VFE = build_voxel_encoder(hard_simple_VFE_cfg)
+    features = torch.rand([240000, 10, 5])
+    num_voxels = torch.randint(1, 10, [240000])
+
+    outputs = hard_simple_VFE(features, num_voxels, None)
+    assert outputs.shape == torch.Size([240000, 5])