Files
Pointnet2_PyTorch/utils/pointnet2_modules.py
T
wassname 9046814dc6 clean up
2018-04-10 13:40:05 +08:00

238 lines
6.9 KiB
Python

import torch
import torch.nn as nn
import torch.nn.functional as F
import pointnet2_utils
import pytorch_utils as pt_utils
from typing import List
class _PointnetSAModuleBase(nn.Module):
def __init__(self):
super().__init__()
self.npoint = None
self.groupers = None
self.mlps = None
def forward(self, xyz: torch.Tensor,
points: torch.Tensor = None) -> (torch.Tensor, torch.Tensor):
r"""
Parameters
----------
xyz : torch.Tensor
(B, N, 3) tensor of the xyz coordinates of the points
points : torch.Tensor
(B, N, C) tensor of the descriptors of the the points
Returns
-------
new_xyz : torch.Tensor
(B, npoint, 3) tensor of the new points' xyz
new_points : torch.Tensor
(B, npoint, \sum_k(mlps[k][-1])) tensor of the new_points descriptors
"""
new_points_list = []
xyz_flipped = xyz.transpose(1, 2).contiguous()
new_xyz = pointnet2_utils.gather_points(
xyz_flipped,
pointnet2_utils.furthest_point_sample(xyz, self.npoint)
).transpose(1, 2).contiguous() if self.npoint is not None else None
for i in range(len(self.groupers)):
new_points = self.groupers[i](
xyz, new_xyz, points
) # (B, C, npoint, nsample)
new_points = self.mlps[i](
new_points
) # (B, mlp[-1], npoint, nsample)
new_points = F.max_pool2d(
new_points, kernel_size=[1, new_points.size(3)]
) # (B, mlp[-1], npoint, 1)
new_points = new_points.squeeze(-1) # (B, mlp[-1], npoint)
new_points_list.append(new_points)
return new_xyz, torch.cat(new_points_list, dim=1)
class PointnetSAModuleMSG(_PointnetSAModuleBase):
r"""Pointnet set abstrction layer with multiscale grouping
Parameters
----------
npoint : int
Number of points
radii : list of float32
list of radii to group with
nsamples : list of int32
Number of samples in each ball query
mlps : list of list of int32
Spec of the pointnet before the global max_pool for each scale
bn : bool
Use batchnorm
"""
def __init__(
self,
*,
npoint: int,
radii: List[float],
nsamples: List[int],
mlps: List[List[int]],
bn: bool = True,
use_xyz: bool = True
):
super().__init__()
assert len(radii) == len(nsamples) == len(mlps)
self.npoint = npoint
self.groupers = nn.ModuleList()
self.mlps = nn.ModuleList()
for i in range(len(radii)):
radius = radii[i]
nsample = nsamples[i]
self.groupers.append(
pointnet2_utils.QueryAndGroup(radius, nsample, use_xyz=use_xyz)
)
mlp_spec = mlps[i]
if use_xyz:
mlp_spec[0] += 3
self.mlps.append(pt_utils.SharedMLP(mlp_spec, bn=bn))
class PointnetSAModule(_PointnetSAModuleBase):
r"""Pointnet set abstrction layer
Parameters
----------
npoint : int
Number of points
radius : float
Radius of ball
nsample : int
Number of samples in the ball query
mlp : list
Spec of the pointnet before the global max_pool
bn : bool
Use batchnorm
"""
def __init__(
self,
*,
mlp: List[int],
npoint: int = None,
radius: float = None,
nsample: int = None,
bn: bool = True,
use_xyz: bool = True
):
super().__init__()
self.npoint = npoint
self.groupers = nn.ModuleList()
self.mlps = nn.ModuleList()
if self.npoint is not None:
assert radius is not None
assert nsample is not None
self.groupers.append(
pointnet2_utils.QueryAndGroup(radius, nsample, use_xyz=use_xyz)
)
else:
self.groupers.append(pointnet2_utils.GroupAll(use_xyz=use_xyz))
if use_xyz:
mlp[0] += 3
self.mlps.append(pt_utils.SharedMLP(mlp, bn=bn))
class PointnetFPModule(nn.Module):
r"""Propigates the features of one set to another
Parameters
----------
mlp : list
Pointnet module parameters
bn : bool
Use batchnorm
"""
def __init__(self, *, mlp: List[int], bn: bool = True):
super().__init__()
self.mlp = pt_utils.SharedMLP(mlp, bn=bn)
def forward(
self, unknown: torch.Tensor, known: torch.Tensor,
unknow_feats: torch.Tensor, known_feats: torch.Tensor
) -> torch.Tensor:
r"""
Parameters
----------
unknown : torch.Tensor
(B, n, 3) tensor of the xyz positions of the unknown points
known : torch.Tensor
(B, m, 3) tensor of the xyz positions of the known points
unknow_feats : torch.Tensor
(B, C1, n) tensor of the features to be propigated to
known_feats : torch.Tensor
(B, C2, m) tensor of features to be propigated
Returns
-------
new_points : torch.Tensor
(B, mlp[-1], n) tensor of the features of the unknown points
"""
dist, idx = pointnet2_utils.three_nn(unknown, known)
dist_recip = 1.0 / (dist + 1e-8)
norm = torch.sum(dist_recip, dim=2, keepdim=True)
weight = dist_recip / norm
interpolated_feats = pointnet2_utils.three_interpolate(
known_feats, idx, weight
)
if unknow_feats is not None:
new_points = torch.cat([interpolated_feats, unknow_feats],
dim=1) #(B, C2 + C1, n)
else:
new_points = interpolated_feats
new_points = new_points.unsqueeze(-1)
new_points = self.mlp(new_points)
return new_points.squeeze(-1)
if __name__ == "__main__":
from torch.autograd import Variable
torch.manual_seed(1)
torch.cuda.manual_seed_all(1)
xyz = Variable(torch.randn(2, 9, 3).cuda(), requires_grad=True)
xyz_feats = Variable(torch.randn(2, 9, 6).cuda(), requires_grad=True)
test_module = PointnetSAModuleMSG(
npoint=2, radii=[5.0, 10.0], nsamples=[6, 3], mlps=[[9, 3], [9, 6]]
)
test_module.cuda()
print(test_module(xyz, xyz_feats))
# test_module = PointnetFPModule(mlp=[6, 6])
# test_module.cuda()
# from torch.autograd import gradcheck
# inputs = (xyz, xyz, None, xyz_feats)
# test = gradcheck(test_module, inputs, eps=1e-6, atol=1e-4)
# print(test)
for _ in range(1):
_, new_points = test_module(xyz, xyz_feats)
new_points.backward(torch.cuda.FloatTensor(*new_points.size()).fill_(1))
print(new_points)
print(xyz.grad)