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
|
// Copyright 2022 DeepMind Technologies Limited
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Tests for engine/engine_util_spatial.c
#include <cmath>
#include <vector>
#include <gmock/gmock.h>
#include <gtest/gtest.h>
#include <mujoco/mjmodel.h>
#include <mujoco/mjtnum.h>
#include "src/engine/engine_util_blas.h"
#include "src/engine/engine_util_spatial.h"
#include "test/fixture.h"
namespace mujoco {
namespace {
using ::testing::ElementsAre;
using Quat2MatTest = MujocoTest;
std::vector<mjtNum> AsVector(const mjtNum* array, int n) {
return std::vector<mjtNum>(array, array + n);
}
TEST_F(Quat2MatTest, NoRotation) {
mjtNum result[9] = {0};
mjtNum quat[] = {1, 0, 0, 0};
mju_quat2Mat(result, quat);
EXPECT_THAT(
AsVector(result, 9),
ElementsAre(1, 0, 0,
0, 1, 0,
0, 0, 1)
);
}
TEST_F(Quat2MatTest, TinyRotation) {
mjtNum result[9] = {0};
// An angle so small that cos(angle) == 1.0 to double accuracy
mjtNum angle = 1e-8;
mjtNum quat[] = {cos(angle/2), sin(angle/2), 0, 0};
mju_quat2Mat(result, quat);
EXPECT_THAT(
AsVector(result, 9),
ElementsAre(1, 0 , 0 ,
0, cos(angle), -sin(angle),
0, sin(angle), cos(angle))
);
}
using MulQuatTest = MujocoTest;
TEST_F(MulQuatTest, TinyRotation) {
mjtNum null_quat[4] = {1, 0, 0, 0};
mjtNum result[4];
// An angle so small that cos(angle) == 1.0 to double accuracy
mjtNum angle = 1e-8;
mjtNum quat[] = {cos(angle/2), sin(angle/2), 0, 0};
mju_mulQuat(result, null_quat, quat);
EXPECT_THAT(
AsVector(result, 4),
ElementsAre(cos(angle/2), sin(angle/2), 0, 0)
);
}
using RotVecQuatTest = MujocoTest;
TEST_F(RotVecQuatTest, NoRotation) {
mjtNum result[3];
mjtNum vec[] = {1, 2, 3};
mjtNum quat[] = {1, 0, 0, 0};
mju_rotVecQuat(result, vec, quat);
EXPECT_THAT(
AsVector(result, 3),
ElementsAre(1, 2, 3)
);
}
TEST_F(RotVecQuatTest, TinyRotation) {
mjtNum result[3];
mjtNum vec[] = {0, 1, 0};
// An angle so small that cos(angle) == 1.0 to double accuracy
mjtNum angle = 1e-8;
mjtNum quat[] = {cos(angle/2), sin(angle/2), 0, 0};
mju_rotVecQuat(result, vec, quat);
EXPECT_THAT(
AsVector(result, 3),
ElementsAre(0, cos(angle), sin(angle))
);
}
// Alternative way of rotating a vector by explicitly converting the quaternion to a 3x3 matrix
void RotVecQuatWithMatrix(mjtNum res[3], const mjtNum vec[3], const mjtNum quat[4]) {
if (quat[0]==1 && quat[1]==0 && quat[2]==0 && quat[3]==0) {
mju_copy3(res, vec);
} else {
mjtNum mat[9];
mju_quat2Mat(mat, quat);
mju_rotVecMat(res, vec, mat);
}
}
TEST_F(RotVecQuatTest, TestEquivalence) {
mjtNum resultActual[3], resultExpected[3], quat[4];
// List of rotation axes
mjtNum vecs[5][3] = {
{1, 0, 0}, {0, 1, 0}, {0, 0, 1}, {-0.5, 1, -0.5}, {1.22, -2.33, 3.44}};
// List of angles to rotate by, in degrees
mjtNum angles[6] = {0.0, 1e-8, 31, 47, 181, 271};
static const mjtNum eps = 1e-15;
for (auto vec: vecs) {
// Unit-normalize the vector
mju_normalize3(vec);
for (auto angleDegree: angles) {
// Convert the axis-angle to a quaternion
auto angleRad = angleDegree * mjPI / 180;
mju_axisAngle2Quat(quat, vec, angleRad);
// Rotate
mju_rotVecQuat(resultActual, vec, quat);
RotVecQuatWithMatrix(resultExpected, vec, quat);
// Compare
EXPECT_NEAR(resultExpected[0], resultActual[0], eps);
EXPECT_NEAR(resultExpected[1], resultActual[1], eps);
EXPECT_NEAR(resultExpected[2], resultActual[2], eps);
}
}
}
} // namespace
} // namespace mujoco
|
