File size: 7,712 Bytes
7088d16
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
# 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 torch
from pytorch3d.ops.interp_face_attrs import (
    interpolate_face_attributes,
    interpolate_face_attributes_python,
)
from pytorch3d.renderer.mesh import TexturesVertex
from pytorch3d.renderer.mesh.rasterizer import Fragments
from pytorch3d.structures import Meshes

from .common_testing import get_random_cuda_device, TestCaseMixin


class TestInterpolateFaceAttributes(TestCaseMixin, unittest.TestCase):
    def _test_interp_face_attrs(self, interp_fun, device):
        pix_to_face = [0, 2, -1, 0, 1, -1]
        barycentric_coords = [
            [1.0, 0.0, 0.0],
            [0.0, 1.0, 0.0],
            [0.0, 0.0, 1.0],
            [0.5, 0.5, 0.0],
            [0.8, 0.0, 0.2],
            [0.25, 0.5, 0.25],
        ]
        face_attrs = [
            [[1, 2], [3, 4], [5, 6]],
            [[7, 8], [9, 10], [11, 12]],
            [[13, 14], [15, 16], [17, 18]],
        ]
        pix_attrs = [
            [1, 2],
            [15, 16],
            [0, 0],
            [2, 3],
            [0.8 * 7 + 0.2 * 11, 0.8 * 8 + 0.2 * 12],
            [0, 0],
        ]
        N, H, W, K, D = 1, 2, 1, 3, 2
        pix_to_face = torch.tensor(pix_to_face, dtype=torch.int64, device=device)
        pix_to_face = pix_to_face.view(N, H, W, K)
        barycentric_coords = torch.tensor(
            barycentric_coords, dtype=torch.float32, device=device
        )
        barycentric_coords = barycentric_coords.view(N, H, W, K, 3)
        face_attrs = torch.tensor(face_attrs, dtype=torch.float32, device=device)
        pix_attrs = torch.tensor(pix_attrs, dtype=torch.float32, device=device)
        pix_attrs = pix_attrs.view(N, H, W, K, D)

        args = (pix_to_face, barycentric_coords, face_attrs)
        pix_attrs_actual = interp_fun(*args)
        self.assertClose(pix_attrs_actual, pix_attrs)

    def test_python(self):
        device = torch.device("cuda:0")
        self._test_interp_face_attrs(interpolate_face_attributes_python, device)

    def test_cuda(self):
        device = torch.device("cuda:0")
        self._test_interp_face_attrs(interpolate_face_attributes, device)

    def test_python_vs_cuda(self):
        N, H, W, K = 2, 32, 32, 5
        F = 1000
        D = 3
        device = get_random_cuda_device()
        torch.manual_seed(598)
        pix_to_face = torch.randint(-F, F, (N, H, W, K), device=device)
        barycentric_coords = torch.randn(
            N, H, W, K, 3, device=device, requires_grad=True
        )
        face_attrs = torch.randn(F, 3, D, device=device, requires_grad=True)
        grad_pix_attrs = torch.randn(N, H, W, K, D, device=device)
        args = (pix_to_face, barycentric_coords, face_attrs)

        # Run the python version
        pix_attrs_py = interpolate_face_attributes_python(*args)
        pix_attrs_py.backward(gradient=grad_pix_attrs)
        grad_bary_py = barycentric_coords.grad.clone()
        grad_face_attrs_py = face_attrs.grad.clone()

        # Clear gradients
        barycentric_coords.grad.zero_()
        face_attrs.grad.zero_()

        # Run the CUDA version
        pix_attrs_cu = interpolate_face_attributes(*args)
        pix_attrs_cu.backward(gradient=grad_pix_attrs)
        grad_bary_cu = barycentric_coords.grad.clone()
        grad_face_attrs_cu = face_attrs.grad.clone()

        # Check they are the same
        self.assertClose(pix_attrs_py, pix_attrs_cu, rtol=2e-3)
        self.assertClose(grad_bary_py, grad_bary_cu, rtol=1e-4)
        self.assertClose(grad_face_attrs_py, grad_face_attrs_cu, rtol=1e-3)

    def test_interpolate_attributes(self):
        verts = torch.randn((4, 3), dtype=torch.float32)
        faces = torch.tensor([[2, 1, 0], [3, 1, 0]], dtype=torch.int64)
        vert_tex = torch.tensor(
            [[0, 1, 0], [0, 1, 1], [1, 1, 0], [1, 1, 1]], dtype=torch.float32
        )
        tex = TexturesVertex(verts_features=vert_tex[None, :])
        mesh = Meshes(verts=[verts], faces=[faces], textures=tex)
        pix_to_face = torch.tensor([0, 1], dtype=torch.int64).view(1, 1, 1, 2)
        barycentric_coords = torch.tensor(
            [[0.5, 0.3, 0.2], [0.3, 0.6, 0.1]], dtype=torch.float32
        ).view(1, 1, 1, 2, -1)
        expected_vals = torch.tensor(
            [[0.5, 1.0, 0.3], [0.3, 1.0, 0.9]], dtype=torch.float32
        ).view(1, 1, 1, 2, -1)
        fragments = Fragments(
            pix_to_face=pix_to_face,
            bary_coords=barycentric_coords,
            zbuf=torch.ones_like(pix_to_face),
            dists=torch.ones_like(pix_to_face),
        )

        verts_features_packed = mesh.textures.verts_features_packed()
        faces_verts_features = verts_features_packed[mesh.faces_packed()]

        texels = interpolate_face_attributes(
            fragments.pix_to_face, fragments.bary_coords, faces_verts_features
        )
        self.assertTrue(torch.allclose(texels, expected_vals[None, :]))

    def test_interpolate_attributes_grad(self):
        verts = torch.randn((4, 3), dtype=torch.float32)
        faces = torch.tensor([[2, 1, 0], [3, 1, 0]], dtype=torch.int64)
        vert_tex = torch.tensor(
            [[0, 1, 0], [0, 1, 1], [1, 1, 0], [1, 1, 1]],
            dtype=torch.float32,
            requires_grad=True,
        )
        tex = TexturesVertex(verts_features=vert_tex[None, :])
        mesh = Meshes(verts=[verts], faces=[faces], textures=tex)
        pix_to_face = torch.tensor([0, 1], dtype=torch.int64).view(1, 1, 1, 2)
        barycentric_coords = torch.tensor(
            [[0.5, 0.3, 0.2], [0.3, 0.6, 0.1]], dtype=torch.float32
        ).view(1, 1, 1, 2, -1)
        fragments = Fragments(
            pix_to_face=pix_to_face,
            bary_coords=barycentric_coords,
            zbuf=torch.ones_like(pix_to_face),
            dists=torch.ones_like(pix_to_face),
        )
        grad_vert_tex = torch.tensor(
            [[0.3, 0.3, 0.3], [0.9, 0.9, 0.9], [0.5, 0.5, 0.5], [0.3, 0.3, 0.3]],
            dtype=torch.float32,
        )
        verts_features_packed = mesh.textures.verts_features_packed()
        faces_verts_features = verts_features_packed[mesh.faces_packed()]

        texels = interpolate_face_attributes(
            fragments.pix_to_face, fragments.bary_coords, faces_verts_features
        )
        texels.sum().backward()
        self.assertTrue(hasattr(vert_tex, "grad"))
        self.assertTrue(torch.allclose(vert_tex.grad, grad_vert_tex[None, :]))

    def test_interpolate_face_attributes_fail(self):
        # 1. A face can only have 3 verts
        #   i.e. face_attributes must have shape (F, 3, D)
        face_attributes = torch.ones(1, 4, 3)
        pix_to_face = torch.ones((1, 1, 1, 1))
        fragments = Fragments(
            pix_to_face=pix_to_face,
            bary_coords=pix_to_face[..., None].expand(-1, -1, -1, -1, 3),
            zbuf=pix_to_face,
            dists=pix_to_face,
        )
        with self.assertRaises(ValueError):
            interpolate_face_attributes(
                fragments.pix_to_face, fragments.bary_coords, face_attributes
            )

        # 2. pix_to_face must have shape (N, H, W, K)
        pix_to_face = torch.ones((1, 1, 1, 1, 3))
        fragments = Fragments(
            pix_to_face=pix_to_face,
            bary_coords=pix_to_face,
            zbuf=pix_to_face,
            dists=pix_to_face,
        )
        with self.assertRaises(ValueError):
            interpolate_face_attributes(
                fragments.pix_to_face, fragments.bary_coords, face_attributes
            )