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17 package org.apache.commons.geometry.enclosing.euclidean.threed;
18
19 import java.util.ArrayList;
20 import java.util.Arrays;
21 import java.util.List;
22
23 import org.apache.commons.geometry.core.GeometryTestUtils;
24 import org.apache.commons.geometry.core.precision.DoublePrecisionContext;
25 import org.apache.commons.geometry.core.precision.EpsilonDoublePrecisionContext;
26 import org.apache.commons.geometry.enclosing.EnclosingBall;
27 import org.apache.commons.geometry.euclidean.threed.Vector3D;
28 import org.apache.commons.rng.UniformRandomProvider;
29 import org.apache.commons.rng.sampling.UnitSphereSampler;
30 import org.apache.commons.rng.simple.RandomSource;
31 import org.junit.Assert;
32 import org.junit.Test;
33
34 public class WelzlEncloser3DTest {
35
36 private static final double TEST_EPS = 1e-10;
37
38 private static final DoublePrecisionContext TEST_PRECISION =
39 new EpsilonDoublePrecisionContext(TEST_EPS);
40
41 private final WelzlEncloser3D encloser = new WelzlEncloser3D(TEST_PRECISION);
42
43 @Test
44 public void testNoPoints() {
45
46 final String msg = "Unable to generate enclosing ball: no points given";
47
48
49 GeometryTestUtils.assertThrows(() -> {
50 encloser.enclose(null);
51 }, IllegalArgumentException.class, msg);
52
53 GeometryTestUtils.assertThrows(() -> {
54 encloser.enclose(new ArrayList<Vector3D>());
55 }, IllegalArgumentException.class, msg);
56 }
57
58 @Test
59 public void testReducingBall() {
60
61 final List<Vector3D> list =
62 Arrays.asList(Vector3D.of(-7.140397329568118, -16.571661242582177, 11.714458961735405),
63 Vector3D.of(-7.137986707455888, -16.570767323375720, 11.708602108715928),
64 Vector3D.of(-7.139185068549035, -16.570891204702250, 11.715554057357394),
65 Vector3D.of(-7.142682716997507, -16.571609818234290, 11.710787934580328),
66 Vector3D.of(-7.139018392423351, -16.574405614157020, 11.710518716711425),
67 Vector3D.of(-7.140870659936730, -16.567993074240455, 11.710914678204503),
68 Vector3D.of(-7.136350173659562, -16.570498228820930, 11.713965225900928),
69 Vector3D.of(-7.141675762759172, -16.572852471407028, 11.714033471449508),
70 Vector3D.of(-7.140453077221105, -16.570212820780647, 11.708624578004980),
71 Vector3D.of(-7.140322188726825, -16.574152894557717, 11.710305611121410),
72 Vector3D.of(-7.141116131477088, -16.574061164624560, 11.712938509321699));
73
74
75 final EnclosingBall<Vector3D> ball = encloser.enclose(list);
76
77
78 Assert.assertTrue(ball.getRadius() > 0);
79 }
80
81 @Test
82 public void testInfiniteLoop() {
83
84
85 final List<Vector3D> list =
86 Arrays.asList(Vector3D.of(-0.89227075512164380, -2.89317694645713900, 14.84572323743355500),
87 Vector3D.of(-0.92099498940693580, -2.31086108263908940, 12.92071026467688300),
88 Vector3D.of(-0.85227999411005200, -3.06314731441320730, 15.40163831651287000),
89 Vector3D.of(-1.77399413020785970, -3.65630391378114260, 14.13190097751873400),
90 Vector3D.of(0.33157833272465354, -2.22813591757792160, 14.21225234159008200),
91 Vector3D.of(-1.53065579165484400, -1.65692084770139570, 14.61483055714788500),
92 Vector3D.of(-1.08457093941217140, -1.96100325935602980, 13.09265170575555000),
93 Vector3D.of(0.30029469589708850, -3.05470831395667370, 14.56352400426342600),
94 Vector3D.of(-0.95007443938638460, -1.86810946486118360, 15.14491234340057000),
95 Vector3D.of(-1.89661503804130830, -2.17004080885185860, 14.81235128513927000),
96 Vector3D.of(-0.72193328761607530, -1.44513142833618270, 14.52355724218561800),
97 Vector3D.of(-0.26895980939606550, -3.69512371522084140, 14.72272846327652000),
98 Vector3D.of(-1.53501693431786170, -3.25055166611021900, 15.15509062584274800),
99 Vector3D.of(-0.71727553535519410, -3.62284279460799100, 13.26256700929380700),
100 Vector3D.of(-0.30220950676137365, -3.25410412500779070, 13.13682612771606000),
101 Vector3D.of(-0.04543996608267075, -1.93081853923797750, 14.79497997883171400),
102 Vector3D.of(-1.53348892951571640, -3.66688919703524900, 14.73095600812074200),
103 Vector3D.of(-0.98034899533935820, -3.34004481162763960, 13.03245014017556800));
104
105
106 final EnclosingBall<Vector3D> ball = encloser.enclose(list);
107
108
109 Assert.assertTrue(ball.getRadius() > 0);
110 }
111
112 @Test
113 public void testLargeSamples() {
114
115 final UniformRandomProvider random = RandomSource.create(RandomSource.WELL_1024_A,
116 0x35ddecfc78131e1dL);
117 final UnitSphereSampler sr = new UnitSphereSampler(3, random);
118 for (int k = 0; k < 50; ++k) {
119
120
121 final double d = 25 * random.nextDouble();
122 final double refRadius = 10 * random.nextDouble();
123 final Vector3D refCenter = Vector3D.linearCombination(d, Vector3D.of(sr.nextVector()));
124
125 final int nbPoints = random.nextInt(1000);
126
127 final List<Vector3D> points = new ArrayList<>();
128 for (int i = 0; i < nbPoints; ++i) {
129 final double r = refRadius * random.nextDouble();
130 points.add(Vector3D.linearCombination(1.0, refCenter, r, Vector3D.of(sr.nextVector())));
131 }
132
133
134
135 checkSphere(points, refRadius);
136 }
137 }
138
139 private void checkSphere(final List<Vector3D> points, final double refRadius) {
140
141 final EnclosingBall<Vector3D> sphere = checkSphere(points);
142
143
144 Assert.assertTrue(sphere.getRadius() <= refRadius);
145
146
147 for (int i = 0; i < sphere.getSupportSize(); ++i) {
148 final List<Vector3D> reducedSupport = new ArrayList<>();
149 int count = 0;
150 for (final Vector3D s : sphere.getSupport()) {
151 if (count++ != i) {
152 reducedSupport.add(s);
153 }
154 }
155 final EnclosingBall<Vector3D> reducedSphere = new SphereGenerator(TEST_PRECISION)
156 .ballOnSupport(reducedSupport);
157 boolean foundOutside = false;
158 for (int j = 0; j < points.size() && !foundOutside; ++j) {
159 if (!reducedSphere.contains(points.get(j), TEST_PRECISION)) {
160 foundOutside = true;
161 }
162 }
163 Assert.assertTrue(foundOutside);
164 }
165 }
166
167 private EnclosingBall<Vector3D> checkSphere(final List<Vector3D> points) {
168
169 final EnclosingBall<Vector3D> sphere = encloser.enclose(points);
170
171
172 for (final Vector3D v : points) {
173 Assert.assertTrue(sphere.contains(v, TEST_PRECISION));
174 }
175
176
177 final Vector3D center = sphere.getCenter();
178 final double radius = sphere.getRadius();
179
180 for (final Vector3D s : sphere.getSupport()) {
181 Assert.assertTrue(TEST_PRECISION.eqZero(center.distance(s) - radius));
182 }
183
184 return sphere;
185 }
186 }