pytorch3d/tests/test_point_mesh_distance.py
Tim Hatch 34bbb3ad32 apply import merging for fbcode/vision/fair (2 of 2)
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When merging imports, µsort will make a best-effort to move associated
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Reviewed By: bottler

Differential Revision: D35553814

fbshipit-source-id: be49bdb6a4c25264ff8d4db3a601f18736d17be1
2022-04-13 06:51:33 -07:00

938 lines
35 KiB
Python

# Copyright (c) Meta Platforms, Inc. and affiliates.
# All rights reserved.
#
# This source code is licensed under the BSD-style license found in the
# LICENSE file in the root directory of this source tree.
import unittest
import numpy as np
import torch
from common_testing import get_random_cuda_device, TestCaseMixin
from pytorch3d import _C
from pytorch3d.loss import point_mesh_edge_distance, point_mesh_face_distance
from pytorch3d.structures import Meshes, packed_to_list, Pointclouds
class TestPointMeshDistance(TestCaseMixin, unittest.TestCase):
def setUp(self) -> None:
np.random.seed(42)
torch.manual_seed(42)
@staticmethod
def eps():
return 1e-8
@staticmethod
def min_triangle_area():
return 5e-3
@staticmethod
def init_meshes_clouds(
batch_size: int = 10,
num_verts: int = 1000,
num_faces: int = 3000,
num_points: int = 3000,
device: str = "cuda:0",
):
device = torch.device(device)
nump = torch.randint(low=1, high=num_points, size=(batch_size,))
numv = torch.randint(low=3, high=num_verts, size=(batch_size,))
numf = torch.randint(low=1, high=num_faces, size=(batch_size,))
verts_list = []
faces_list = []
points_list = []
for i in range(batch_size):
# Randomly choose vertices
verts = torch.rand((numv[i], 3), dtype=torch.float32, device=device)
verts.requires_grad_(True)
# Randomly choose faces. Our tests below compare argmin indices
# over faces and edges. Argmin is sensitive even to small numeral variations
# thus we make sure that faces are valid
# i.e. a face f = (i0, i1, i2) s.t. i0 != i1 != i2,
# otherwise argmin due to numeral sensitivities cannot be resolved
faces, allf = [], 0
validf = numv[i].item() - numv[i].item() % 3
while allf < numf[i]:
ff = torch.randperm(numv[i], device=device)[:validf].view(-1, 3)
faces.append(ff)
allf += ff.shape[0]
faces = torch.cat(faces, 0)
if faces.shape[0] > numf[i]:
faces = faces[: numf[i]]
verts_list.append(verts)
faces_list.append(faces)
# Randomly choose points
points = torch.rand((nump[i], 3), dtype=torch.float32, device=device)
points.requires_grad_(True)
points_list.append(points)
meshes = Meshes(verts_list, faces_list)
pcls = Pointclouds(points_list)
return meshes, pcls
@staticmethod
def _point_to_bary(point: torch.Tensor, tri: torch.Tensor) -> torch.Tensor:
"""
Computes the barycentric coordinates of point wrt triangle (tri)
Note that point needs to live in the space spanned by tri = (a, b, c),
i.e. by taking the projection of an arbitrary point on the space spanned by tri
Args:
point: FloatTensor of shape (3)
tri: FloatTensor of shape (3, 3)
Returns:
bary: FloatTensor of shape (3)
"""
assert point.dim() == 1 and point.shape[0] == 3
assert tri.dim() == 2 and tri.shape[0] == 3 and tri.shape[1] == 3
a, b, c = tri.unbind(0)
v0 = b - a
v1 = c - a
v2 = point - a
d00 = v0.dot(v0)
d01 = v0.dot(v1)
d11 = v1.dot(v1)
d20 = v2.dot(v0)
d21 = v2.dot(v1)
denom = d00 * d11 - d01 * d01 + TestPointMeshDistance.eps()
s2 = (d11 * d20 - d01 * d21) / denom
s3 = (d00 * d21 - d01 * d20) / denom
s1 = 1.0 - s2 - s3
bary = torch.tensor([s1, s2, s3])
return bary
@staticmethod
def _is_inside_triangle(point: torch.Tensor, tri: torch.Tensor) -> torch.Tensor:
"""
Computes whether point is inside triangle tri
Note that point needs to live in the space spanned by tri = (a, b, c)
i.e. by taking the projection of an arbitrary point on the space spanned by tri
Args:
point: FloatTensor of shape (3)
tri: FloatTensor of shape (3, 3)
Returns:
inside: BoolTensor of shape (1)
"""
v0 = tri[1] - tri[0]
v1 = tri[2] - tri[0]
area = torch.cross(v0, v1).norm() / 2.0
# check if triangle is a line or a point. In that case, return False
if area < 5e-3:
return False
bary = TestPointMeshDistance._point_to_bary(point, tri)
inside = ((bary >= 0.0) * (bary <= 1.0)).all()
return inside
@staticmethod
def _point_to_edge_distance(
point: torch.Tensor, edge: torch.Tensor
) -> torch.Tensor:
"""
Computes the squared euclidean distance of points to edges
Args:
point: FloatTensor of shape (3)
edge: FloatTensor of shape (2, 3)
Returns:
dist: FloatTensor of shape (1)
If a, b are the start and end points of the segments, we
parametrize a point p as
x(t) = a + t * (b - a)
To find t which describes p we minimize (x(t) - p) ^ 2
Note that p does not need to live in the space spanned by (a, b)
"""
s0, s1 = edge.unbind(0)
s01 = s1 - s0
norm_s01 = s01.dot(s01)
same_edge = norm_s01 < TestPointMeshDistance.eps()
if same_edge:
dist = 0.5 * (point - s0).dot(point - s0) + 0.5 * (point - s1).dot(
point - s1
)
return dist
t = s01.dot(point - s0) / norm_s01
t = torch.clamp(t, min=0.0, max=1.0)
x = s0 + t * s01
dist = (x - point).dot(x - point)
return dist
@staticmethod
def _point_to_tri_distance(point: torch.Tensor, tri: torch.Tensor) -> torch.Tensor:
"""
Computes the squared euclidean distance of points to edges
Args:
point: FloatTensor of shape (3)
tri: FloatTensor of shape (3, 3)
Returns:
dist: FloatTensor of shape (1)
"""
a, b, c = tri.unbind(0)
cross = torch.cross(b - a, c - a)
norm = cross.norm()
normal = torch.nn.functional.normalize(cross, dim=0)
# p0 is the projection of p onto the plane spanned by (a, b, c)
# p0 = p + tt * normal, s.t. (p0 - a) is orthogonal to normal
# => tt = dot(a - p, n)
tt = normal.dot(a) - normal.dot(point)
p0 = point + tt * normal
dist_p = tt * tt
# Compute the distance of p to all edge segments
e01_dist = TestPointMeshDistance._point_to_edge_distance(point, tri[[0, 1]])
e02_dist = TestPointMeshDistance._point_to_edge_distance(point, tri[[0, 2]])
e12_dist = TestPointMeshDistance._point_to_edge_distance(point, tri[[1, 2]])
with torch.no_grad():
inside_tri = TestPointMeshDistance._is_inside_triangle(p0, tri)
if inside_tri and (norm > TestPointMeshDistance.eps()):
return dist_p
else:
if e01_dist.le(e02_dist) and e01_dist.le(e12_dist):
return e01_dist
elif e02_dist.le(e01_dist) and e02_dist.le(e12_dist):
return e02_dist
else:
return e12_dist
def test_point_edge_array_distance(self):
"""
Test CUDA implementation for PointEdgeArrayDistanceForward
& PointEdgeArrayDistanceBackward
"""
P, E = 16, 32
device = get_random_cuda_device()
points = torch.rand((P, 3), dtype=torch.float32, device=device)
edges = torch.rand((E, 2, 3), dtype=torch.float32, device=device)
# randomly make some edge points equal
same = torch.rand((E,), dtype=torch.float32, device=device) > 0.5
edges[same, 1] = edges[same, 0].clone().detach()
points_cpu = points.clone().cpu()
edges_cpu = edges.clone().cpu()
points.requires_grad = True
edges.requires_grad = True
grad_dists = torch.rand((P, E), dtype=torch.float32, device=device)
# Naive python implementation
dists_naive = torch.zeros((P, E), dtype=torch.float32, device=device)
for p in range(P):
for e in range(E):
dist = self._point_to_edge_distance(points[p], edges[e])
dists_naive[p, e] = dist
# Cuda Forward Implementation
dists_cuda = _C.point_edge_array_dist_forward(points, edges)
dists_cpu = _C.point_edge_array_dist_forward(points_cpu, edges_cpu)
# Compare
self.assertClose(dists_naive.cpu(), dists_cuda.cpu())
self.assertClose(dists_naive.cpu(), dists_cpu)
# CUDA Bacwkard Implementation
grad_points_cuda, grad_edges_cuda = _C.point_edge_array_dist_backward(
points, edges, grad_dists
)
grad_points_cpu, grad_edges_cpu = _C.point_edge_array_dist_backward(
points_cpu, edges_cpu, grad_dists.cpu()
)
dists_naive.backward(grad_dists)
grad_points_naive = points.grad.cpu()
grad_edges_naive = edges.grad.cpu()
# Compare
self.assertClose(grad_points_naive, grad_points_cuda.cpu())
self.assertClose(grad_edges_naive, grad_edges_cuda.cpu())
self.assertClose(grad_points_naive, grad_points_cpu)
self.assertClose(grad_edges_naive, grad_edges_cpu)
def test_point_edge_distance(self):
"""
Test CUDA implementation for PointEdgeDistanceForward
& PointEdgeDistanceBackward
"""
device = get_random_cuda_device()
N, V, F, P = 4, 32, 16, 24
meshes, pcls = self.init_meshes_clouds(N, V, F, P, device=device)
# make points packed a leaf node
points_packed = pcls.points_packed().detach().clone() # (P, 3)
points_first_idx = pcls.cloud_to_packed_first_idx()
max_p = pcls.num_points_per_cloud().max().item()
# make edges packed a leaf node
verts_packed = meshes.verts_packed()
edges_packed = verts_packed[meshes.edges_packed()] # (E, 2, 3)
edges_packed = edges_packed.clone().detach()
edges_first_idx = meshes.mesh_to_edges_packed_first_idx()
# leaf nodes
points_packed.requires_grad = True
edges_packed.requires_grad = True
grad_dists = torch.rand(
(points_packed.shape[0],), dtype=torch.float32, device=device
)
# Cuda Implementation: forward
dists_cuda, idx_cuda = _C.point_edge_dist_forward(
points_packed, points_first_idx, edges_packed, edges_first_idx, max_p
)
# Cuda Implementation: backward
grad_points_cuda, grad_edges_cuda = _C.point_edge_dist_backward(
points_packed, edges_packed, idx_cuda, grad_dists
)
# Cpu Implementation: forward
dists_cpu, idx_cpu = _C.point_edge_dist_forward(
points_packed.cpu(),
points_first_idx.cpu(),
edges_packed.cpu(),
edges_first_idx.cpu(),
max_p,
)
# Cpu Implementation: backward
# Note that using idx_cpu doesn't pass - there seems to be a problem with tied results.
grad_points_cpu, grad_edges_cpu = _C.point_edge_dist_backward(
points_packed.cpu(), edges_packed.cpu(), idx_cuda.cpu(), grad_dists.cpu()
)
# Naive Implementation: forward
edges_list = packed_to_list(edges_packed, meshes.num_edges_per_mesh().tolist())
dists_naive = []
for i in range(N):
points = pcls.points_list()[i]
edges = edges_list[i]
dists_temp = torch.zeros(
(points.shape[0], edges.shape[0]), dtype=torch.float32, device=device
)
for p in range(points.shape[0]):
for e in range(edges.shape[0]):
dist = self._point_to_edge_distance(points[p], edges[e])
dists_temp[p, e] = dist
# torch.min() doesn't necessarily return the first index of the
# smallest value, our warp_reduce does. So it's not straightforward
# to directly compare indices, nor the gradients of grad_edges which
# also depend on the indices of the minimum value.
# To be able to compare, we will compare dists_temp.min(1) and
# then feed the cuda indices to the naive output
start = points_first_idx[i]
end = points_first_idx[i + 1] if i < N - 1 else points_packed.shape[0]
min_idx = idx_cuda[start:end] - edges_first_idx[i]
iidx = torch.arange(points.shape[0], device=device)
min_dist = dists_temp[iidx, min_idx]
dists_naive.append(min_dist)
dists_naive = torch.cat(dists_naive)
# Compare
self.assertClose(dists_naive.cpu(), dists_cuda.cpu())
self.assertClose(dists_naive.cpu(), dists_cpu)
# Naive Implementation: backward
dists_naive.backward(grad_dists)
grad_points_naive = torch.cat([cloud.grad for cloud in pcls.points_list()])
grad_edges_naive = edges_packed.grad.cpu()
# Compare
self.assertClose(grad_points_naive.cpu(), grad_points_cuda.cpu(), atol=1e-7)
self.assertClose(grad_edges_naive, grad_edges_cuda.cpu(), atol=5e-7)
self.assertClose(grad_points_naive.cpu(), grad_points_cpu, atol=1e-7)
self.assertClose(grad_edges_naive, grad_edges_cpu, atol=5e-7)
def test_edge_point_distance(self):
"""
Test CUDA implementation for EdgePointDistanceForward
& EdgePointDistanceBackward
"""
device = get_random_cuda_device()
N, V, F, P = 4, 32, 16, 24
meshes, pcls = self.init_meshes_clouds(N, V, F, P, device=device)
# make points packed a leaf node
points_packed = pcls.points_packed().detach().clone() # (P, 3)
points_first_idx = pcls.cloud_to_packed_first_idx()
# make edges packed a leaf node
verts_packed = meshes.verts_packed()
edges_packed = verts_packed[meshes.edges_packed()] # (E, 2, 3)
edges_packed = edges_packed.clone().detach()
edges_first_idx = meshes.mesh_to_edges_packed_first_idx()
max_e = meshes.num_edges_per_mesh().max().item()
# leaf nodes
points_packed.requires_grad = True
edges_packed.requires_grad = True
grad_dists = torch.rand(
(edges_packed.shape[0],), dtype=torch.float32, device=device
)
# Cuda Implementation: forward
dists_cuda, idx_cuda = _C.edge_point_dist_forward(
points_packed, points_first_idx, edges_packed, edges_first_idx, max_e
)
# Cuda Implementation: backward
grad_points_cuda, grad_edges_cuda = _C.edge_point_dist_backward(
points_packed, edges_packed, idx_cuda, grad_dists
)
# Cpu Implementation: forward
dists_cpu, idx_cpu = _C.edge_point_dist_forward(
points_packed.cpu(),
points_first_idx.cpu(),
edges_packed.cpu(),
edges_first_idx.cpu(),
max_e,
)
# Cpu Implementation: backward
grad_points_cpu, grad_edges_cpu = _C.edge_point_dist_backward(
points_packed.cpu(), edges_packed.cpu(), idx_cpu, grad_dists.cpu()
)
# Naive Implementation: forward
edges_list = packed_to_list(edges_packed, meshes.num_edges_per_mesh().tolist())
dists_naive = []
for i in range(N):
points = pcls.points_list()[i]
edges = edges_list[i]
dists_temp = torch.zeros(
(edges.shape[0], points.shape[0]), dtype=torch.float32, device=device
)
for e in range(edges.shape[0]):
for p in range(points.shape[0]):
dist = self._point_to_edge_distance(points[p], edges[e])
dists_temp[e, p] = dist
# torch.min() doesn't necessarily return the first index of the
# smallest value, our warp_reduce does. So it's not straightforward
# to directly compare indices, nor the gradients of grad_edges which
# also depend on the indices of the minimum value.
# To be able to compare, we will compare dists_temp.min(1) and
# then feed the cuda indices to the naive output
start = edges_first_idx[i]
end = edges_first_idx[i + 1] if i < N - 1 else edges_packed.shape[0]
min_idx = idx_cuda.cpu()[start:end] - points_first_idx[i].cpu()
iidx = torch.arange(edges.shape[0], device=device)
min_dist = dists_temp[iidx, min_idx]
dists_naive.append(min_dist)
dists_naive = torch.cat(dists_naive)
# Compare
self.assertClose(dists_naive.cpu(), dists_cuda.cpu())
self.assertClose(dists_naive.cpu(), dists_cpu)
# Naive Implementation: backward
dists_naive.backward(grad_dists)
grad_points_naive = torch.cat([cloud.grad for cloud in pcls.points_list()])
grad_edges_naive = edges_packed.grad.cpu()
# Compare
self.assertClose(grad_points_naive.cpu(), grad_points_cuda.cpu(), atol=1e-7)
self.assertClose(grad_edges_naive, grad_edges_cuda.cpu(), atol=5e-7)
self.assertClose(grad_points_naive.cpu(), grad_points_cpu, atol=1e-7)
self.assertClose(grad_edges_naive, grad_edges_cpu, atol=5e-7)
def test_point_mesh_edge_distance(self):
"""
Test point_mesh_edge_distance from pytorch3d.loss
"""
device = get_random_cuda_device()
N, V, F, P = 4, 32, 16, 24
meshes, pcls = self.init_meshes_clouds(N, V, F, P, device=device)
# clone and detach for another backward pass through the op
verts_op = [verts.clone().detach() for verts in meshes.verts_list()]
for i in range(N):
verts_op[i].requires_grad = True
faces_op = [faces.clone().detach() for faces in meshes.faces_list()]
meshes_op = Meshes(verts=verts_op, faces=faces_op)
points_op = [points.clone().detach() for points in pcls.points_list()]
for i in range(N):
points_op[i].requires_grad = True
pcls_op = Pointclouds(points_op)
# Cuda implementation: forward & backward
loss_op = point_mesh_edge_distance(meshes_op, pcls_op)
# Naive implementation: forward & backward
edges_packed = meshes.edges_packed()
edges_list = packed_to_list(edges_packed, meshes.num_edges_per_mesh().tolist())
loss_naive = torch.zeros(N, dtype=torch.float32, device=device)
for i in range(N):
points = pcls.points_list()[i]
verts = meshes.verts_list()[i]
v_first_idx = meshes.mesh_to_verts_packed_first_idx()[i]
edges = verts[edges_list[i] - v_first_idx]
num_p = points.shape[0]
num_e = edges.shape[0]
dists = torch.zeros((num_p, num_e), dtype=torch.float32, device=device)
for p in range(num_p):
for e in range(num_e):
dist = self._point_to_edge_distance(points[p], edges[e])
dists[p, e] = dist
min_dist_p, min_idx_p = dists.min(1)
min_dist_e, min_idx_e = dists.min(0)
loss_naive[i] = min_dist_p.mean() + min_dist_e.mean()
loss_naive = loss_naive.mean()
# NOTE that hear the comparison holds despite the discrepancy
# due to the argmin indices returned by min(). This is because
# we don't will compare gradients on the verts and not on the
# edges or faces.
# Compare forward pass
self.assertClose(loss_op, loss_naive)
# Compare backward pass
rand_val = torch.rand(1).item()
grad_dist = torch.tensor(rand_val, dtype=torch.float32, device=device)
loss_naive.backward(grad_dist)
loss_op.backward(grad_dist)
# check verts grad
for i in range(N):
self.assertClose(
meshes.verts_list()[i].grad, meshes_op.verts_list()[i].grad
)
self.assertClose(pcls.points_list()[i].grad, pcls_op.points_list()[i].grad)
def test_point_face_array_distance(self):
"""
Test CUDA implementation for PointFaceArrayDistanceForward
& PointFaceArrayDistanceBackward
"""
P, T = 16, 32
device = get_random_cuda_device()
points = torch.rand((P, 3), dtype=torch.float32, device=device)
tris = torch.rand((T, 3, 3), dtype=torch.float32, device=device)
points_cpu = points.clone().cpu()
tris_cpu = tris.clone().cpu()
points.requires_grad = True
tris.requires_grad = True
grad_dists = torch.rand((P, T), dtype=torch.float32, device=device)
points_temp = points.clone().detach()
points_temp.requires_grad = True
tris_temp = tris.clone().detach()
tris_temp.requires_grad = True
# Naive python implementation
dists_naive = torch.zeros((P, T), dtype=torch.float32, device=device)
for p in range(P):
for t in range(T):
dist = self._point_to_tri_distance(points[p], tris[t])
dists_naive[p, t] = dist
# Naive Backward
dists_naive.backward(grad_dists)
grad_points_naive = points.grad.cpu()
grad_tris_naive = tris.grad.cpu()
# Cuda Forward Implementation
dists_cuda = _C.point_face_array_dist_forward(
points, tris, TestPointMeshDistance.min_triangle_area()
)
dists_cpu = _C.point_face_array_dist_forward(
points_cpu, tris_cpu, TestPointMeshDistance.min_triangle_area()
)
# Compare
self.assertClose(dists_naive.cpu(), dists_cuda.cpu())
self.assertClose(dists_naive.cpu(), dists_cpu)
# CUDA Backward Implementation
grad_points_cuda, grad_tris_cuda = _C.point_face_array_dist_backward(
points, tris, grad_dists, TestPointMeshDistance.min_triangle_area()
)
grad_points_cpu, grad_tris_cpu = _C.point_face_array_dist_backward(
points_cpu,
tris_cpu,
grad_dists.cpu(),
TestPointMeshDistance.min_triangle_area(),
)
# Compare
self.assertClose(grad_points_naive, grad_points_cuda.cpu())
self.assertClose(grad_tris_naive, grad_tris_cuda.cpu(), atol=5e-6)
self.assertClose(grad_points_naive, grad_points_cpu)
self.assertClose(grad_tris_naive, grad_tris_cpu, atol=5e-6)
def test_point_face_distance(self):
"""
Test CUDA implementation for PointFaceDistanceForward
& PointFaceDistanceBackward
"""
device = get_random_cuda_device()
N, V, F, P = 4, 32, 16, 24
meshes, pcls = self.init_meshes_clouds(N, V, F, P, device=device)
# make points packed a leaf node
points_packed = pcls.points_packed().detach().clone() # (P, 3)
points_first_idx = pcls.cloud_to_packed_first_idx()
max_p = pcls.num_points_per_cloud().max().item()
# make edges packed a leaf node
verts_packed = meshes.verts_packed()
faces_packed = verts_packed[meshes.faces_packed()] # (T, 3, 3)
faces_packed = faces_packed.clone().detach()
faces_first_idx = meshes.mesh_to_faces_packed_first_idx()
# leaf nodes
points_packed.requires_grad = True
faces_packed.requires_grad = True
grad_dists = torch.rand(
(points_packed.shape[0],), dtype=torch.float32, device=device
)
# Cuda Implementation: forward
dists_cuda, idx_cuda = _C.point_face_dist_forward(
points_packed,
points_first_idx,
faces_packed,
faces_first_idx,
max_p,
TestPointMeshDistance.min_triangle_area(),
)
# Cuda Implementation: backward
grad_points_cuda, grad_faces_cuda = _C.point_face_dist_backward(
points_packed,
faces_packed,
idx_cuda,
grad_dists,
TestPointMeshDistance.min_triangle_area(),
)
# Cpu Implementation: forward
dists_cpu, idx_cpu = _C.point_face_dist_forward(
points_packed.cpu(),
points_first_idx.cpu(),
faces_packed.cpu(),
faces_first_idx.cpu(),
max_p,
TestPointMeshDistance.min_triangle_area(),
)
# Cpu Implementation: backward
# Note that using idx_cpu doesn't pass - there seems to be a problem with tied results.
grad_points_cpu, grad_faces_cpu = _C.point_face_dist_backward(
points_packed.cpu(),
faces_packed.cpu(),
idx_cuda.cpu(),
grad_dists.cpu(),
TestPointMeshDistance.min_triangle_area(),
)
# Naive Implementation: forward
faces_list = packed_to_list(faces_packed, meshes.num_faces_per_mesh().tolist())
dists_naive = []
for i in range(N):
points = pcls.points_list()[i]
tris = faces_list[i]
dists_temp = torch.zeros(
(points.shape[0], tris.shape[0]), dtype=torch.float32, device=device
)
for p in range(points.shape[0]):
for t in range(tris.shape[0]):
dist = self._point_to_tri_distance(points[p], tris[t])
dists_temp[p, t] = dist
# torch.min() doesn't necessarily return the first index of the
# smallest value, our warp_reduce does. So it's not straightforward
# to directly compare indices, nor the gradients of grad_tris which
# also depend on the indices of the minimum value.
# To be able to compare, we will compare dists_temp.min(1) and
# then feed the cuda indices to the naive output
start = points_first_idx[i]
end = points_first_idx[i + 1] if i < N - 1 else points_packed.shape[0]
min_idx = idx_cuda.cpu()[start:end] - faces_first_idx[i].cpu()
iidx = torch.arange(points.shape[0], device=device)
min_dist = dists_temp[iidx, min_idx]
dists_naive.append(min_dist)
dists_naive = torch.cat(dists_naive)
# Compare
self.assertClose(dists_naive.cpu(), dists_cuda.cpu())
self.assertClose(dists_naive.cpu(), dists_cpu)
# Naive Implementation: backward
dists_naive.backward(grad_dists)
grad_points_naive = torch.cat([cloud.grad for cloud in pcls.points_list()])
grad_faces_naive = faces_packed.grad.cpu()
# Compare
self.assertClose(grad_points_naive.cpu(), grad_points_cuda.cpu(), atol=1e-7)
self.assertClose(grad_faces_naive, grad_faces_cuda.cpu(), atol=5e-7)
self.assertClose(grad_points_naive.cpu(), grad_points_cpu, atol=1e-7)
self.assertClose(grad_faces_naive, grad_faces_cpu, atol=5e-7)
def test_face_point_distance(self):
"""
Test CUDA implementation for FacePointDistanceForward
& FacePointDistanceBackward
"""
device = get_random_cuda_device()
N, V, F, P = 4, 32, 16, 24
meshes, pcls = self.init_meshes_clouds(N, V, F, P, device=device)
# make points packed a leaf node
points_packed = pcls.points_packed().detach().clone() # (P, 3)
points_first_idx = pcls.cloud_to_packed_first_idx()
# make edges packed a leaf node
verts_packed = meshes.verts_packed()
faces_packed = verts_packed[meshes.faces_packed()] # (T, 3, 3)
faces_packed = faces_packed.clone().detach()
faces_first_idx = meshes.mesh_to_faces_packed_first_idx()
max_f = meshes.num_faces_per_mesh().max().item()
# leaf nodes
points_packed.requires_grad = True
faces_packed.requires_grad = True
grad_dists = torch.rand(
(faces_packed.shape[0],), dtype=torch.float32, device=device
)
# Cuda Implementation: forward
dists_cuda, idx_cuda = _C.face_point_dist_forward(
points_packed,
points_first_idx,
faces_packed,
faces_first_idx,
max_f,
TestPointMeshDistance.min_triangle_area(),
)
# Cuda Implementation: backward
grad_points_cuda, grad_faces_cuda = _C.face_point_dist_backward(
points_packed,
faces_packed,
idx_cuda,
grad_dists,
TestPointMeshDistance.min_triangle_area(),
)
# Cpu Implementation: forward
dists_cpu, idx_cpu = _C.face_point_dist_forward(
points_packed.cpu(),
points_first_idx.cpu(),
faces_packed.cpu(),
faces_first_idx.cpu(),
max_f,
TestPointMeshDistance.min_triangle_area(),
)
# Cpu Implementation: backward
grad_points_cpu, grad_faces_cpu = _C.face_point_dist_backward(
points_packed.cpu(),
faces_packed.cpu(),
idx_cpu,
grad_dists.cpu(),
TestPointMeshDistance.min_triangle_area(),
)
# Naive Implementation: forward
faces_list = packed_to_list(faces_packed, meshes.num_faces_per_mesh().tolist())
dists_naive = []
for i in range(N):
points = pcls.points_list()[i]
tris = faces_list[i]
dists_temp = torch.zeros(
(tris.shape[0], points.shape[0]), dtype=torch.float32, device=device
)
for t in range(tris.shape[0]):
for p in range(points.shape[0]):
dist = self._point_to_tri_distance(points[p], tris[t])
dists_temp[t, p] = dist
# torch.min() doesn't necessarily return the first index of the
# smallest value, our warp_reduce does. So it's not straightforward
# to directly compare indices, nor the gradients of grad_tris which
# also depend on the indices of the minimum value.
# To be able to compare, we will compare dists_temp.min(1) and
# then feed the cuda indices to the naive output
start = faces_first_idx[i]
end = faces_first_idx[i + 1] if i < N - 1 else faces_packed.shape[0]
min_idx = idx_cuda.cpu()[start:end] - points_first_idx[i].cpu()
iidx = torch.arange(tris.shape[0], device=device)
min_dist = dists_temp[iidx, min_idx]
dists_naive.append(min_dist)
dists_naive = torch.cat(dists_naive)
# Compare
self.assertClose(dists_naive.cpu(), dists_cuda.cpu())
self.assertClose(dists_naive.cpu(), dists_cpu)
# Naive Implementation: backward
dists_naive.backward(grad_dists)
grad_points_naive = torch.cat([cloud.grad for cloud in pcls.points_list()])
grad_faces_naive = faces_packed.grad
# Compare
self.assertClose(grad_points_naive.cpu(), grad_points_cuda.cpu(), atol=1e-7)
self.assertClose(grad_faces_naive.cpu(), grad_faces_cuda.cpu(), atol=5e-7)
self.assertClose(grad_points_naive.cpu(), grad_points_cpu, atol=1e-7)
self.assertClose(grad_faces_naive.cpu(), grad_faces_cpu, atol=5e-7)
def test_point_mesh_face_distance(self):
"""
Test point_mesh_face_distance from pytorch3d.loss
"""
device = get_random_cuda_device()
N, V, F, P = 4, 32, 16, 24
meshes, pcls = self.init_meshes_clouds(N, V, F, P, device=device)
# clone and detach for another backward pass through the op
verts_op = [verts.clone().detach() for verts in meshes.verts_list()]
for i in range(N):
verts_op[i].requires_grad = True
faces_op = [faces.clone().detach() for faces in meshes.faces_list()]
meshes_op = Meshes(verts=verts_op, faces=faces_op)
points_op = [points.clone().detach() for points in pcls.points_list()]
for i in range(N):
points_op[i].requires_grad = True
pcls_op = Pointclouds(points_op)
# naive implementation
loss_naive = torch.zeros(N, dtype=torch.float32, device=device)
for i in range(N):
points = pcls.points_list()[i]
verts = meshes.verts_list()[i]
faces = meshes.faces_list()[i]
tris = verts[faces]
num_p = points.shape[0]
num_t = tris.shape[0]
dists = torch.zeros((num_p, num_t), dtype=torch.float32, device=device)
for p in range(num_p):
for t in range(num_t):
dist = self._point_to_tri_distance(points[p], tris[t])
dists[p, t] = dist
min_dist_p, min_idx_p = dists.min(1)
min_dist_t, min_idx_t = dists.min(0)
loss_naive[i] = min_dist_p.mean() + min_dist_t.mean()
loss_naive = loss_naive.mean()
# Op
loss_op = point_mesh_face_distance(meshes_op, pcls_op)
# Compare forward pass
self.assertClose(loss_op, loss_naive)
# Compare backward pass
rand_val = torch.rand(1).item()
grad_dist = torch.tensor(rand_val, dtype=torch.float32, device=device)
loss_naive.backward(grad_dist)
loss_op.backward(grad_dist)
# check verts grad
for i in range(N):
self.assertClose(
meshes.verts_list()[i].grad, meshes_op.verts_list()[i].grad
)
self.assertClose(pcls.points_list()[i].grad, pcls_op.points_list()[i].grad)
def test_small_faces_case(self):
for device in [torch.device("cpu"), torch.device("cuda:0")]:
mesh_vertices = torch.tensor(
[
[-0.0021, -0.3769, 0.7146],
[-0.0161, -0.3771, 0.7146],
[-0.0021, -0.3771, 0.7147],
],
dtype=torch.float32,
device=device,
)
mesh1_faces = torch.tensor([[0, 2, 1]], device=device)
mesh2_faces = torch.tensor([[2, 0, 1]], device=device)
pcd_points = torch.tensor([[-0.3623, -0.5340, 0.7727]], device=device)
mesh1 = Meshes(verts=[mesh_vertices], faces=[mesh1_faces])
mesh2 = Meshes(verts=[mesh_vertices], faces=[mesh2_faces])
pcd = Pointclouds(points=[pcd_points])
loss1 = point_mesh_face_distance(mesh1, pcd)
loss2 = point_mesh_face_distance(mesh2, pcd)
self.assertClose(loss1, loss2)
@staticmethod
def point_mesh_edge(N: int, V: int, F: int, P: int, device: str):
device = torch.device(device)
meshes, pcls = TestPointMeshDistance.init_meshes_clouds(
N, V, F, P, device=device
)
torch.cuda.synchronize()
def loss():
point_mesh_edge_distance(meshes, pcls)
torch.cuda.synchronize()
return loss
@staticmethod
def point_mesh_face(N: int, V: int, F: int, P: int, device: str):
device = torch.device(device)
meshes, pcls = TestPointMeshDistance.init_meshes_clouds(
N, V, F, P, device=device
)
torch.cuda.synchronize()
def loss():
point_mesh_face_distance(meshes, pcls)
torch.cuda.synchronize()
return loss