1 | #include "Ray.h"
|
---|
2 | #include "Mesh.h"
|
---|
3 | #include "MeshKdTree.h"
|
---|
4 |
|
---|
5 | int MeshInstance::mailID = 21843194198;
|
---|
6 |
|
---|
7 | void
|
---|
8 | Mesh::Preprocess()
|
---|
9 | {
|
---|
10 | mBoundingBox.Initialize();
|
---|
11 |
|
---|
12 | VertexContainer::const_iterator vi = mVertices.begin();
|
---|
13 | for (; vi != mVertices.end(); vi++) {
|
---|
14 | mBoundingBox.Include(*vi);
|
---|
15 | }
|
---|
16 |
|
---|
17 | mIsConvex = false;
|
---|
18 |
|
---|
19 | if (mFaces.size() > 2*MeshKdTree::mTermMinCost) {
|
---|
20 | mKdTree = new MeshKdTree(this);
|
---|
21 | MeshKdLeaf *root = (MeshKdLeaf *)mKdTree->GetRoot();
|
---|
22 | for (int i = 0; i < mFaces.size(); i++)
|
---|
23 | root->mFaces.push_back(i);
|
---|
24 | cout<<"KD";
|
---|
25 | mKdTree->Construct();
|
---|
26 | }
|
---|
27 | }
|
---|
28 |
|
---|
29 | AxisAlignedBox3
|
---|
30 | Mesh::GetFaceBox(const int faceIndex)
|
---|
31 | {
|
---|
32 | Face *face = mFaces[faceIndex];
|
---|
33 | AxisAlignedBox3 box;
|
---|
34 | box.SetMin( mVertices[face->mVertexIndices[0]] );
|
---|
35 | box.SetMax(box.Min());
|
---|
36 | for (int i = 1; i < face->mVertexIndices.size(); i++) {
|
---|
37 | box.Include(mVertices[face->mVertexIndices[i]]);
|
---|
38 | }
|
---|
39 | return box;
|
---|
40 | }
|
---|
41 |
|
---|
42 | int
|
---|
43 | Mesh::CastRayToFace(
|
---|
44 | const int faceIndex,
|
---|
45 | Ray &ray,
|
---|
46 | float &nearestT,
|
---|
47 | int &nearestFace,
|
---|
48 | MeshInstance *instance
|
---|
49 | )
|
---|
50 | {
|
---|
51 | float t;
|
---|
52 | int hit = 0;
|
---|
53 | if (RayFaceIntersection(faceIndex, ray, t, nearestT) == Ray::INTERSECTION) {
|
---|
54 | switch (ray.GetType()) {
|
---|
55 | case Ray::GLOBAL_RAY:
|
---|
56 | ray.intersections.push_back(Ray::RayIntersection(t, instance, faceIndex));
|
---|
57 | hit++;
|
---|
58 | break;
|
---|
59 | case Ray::LOCAL_RAY:
|
---|
60 | nearestT = t;
|
---|
61 | nearestFace = faceIndex;
|
---|
62 | hit++;
|
---|
63 | break;
|
---|
64 | }
|
---|
65 | }
|
---|
66 | return hit;
|
---|
67 | }
|
---|
68 |
|
---|
69 | int
|
---|
70 | Mesh::CastRay(
|
---|
71 | Ray &ray,
|
---|
72 | MeshInstance *instance
|
---|
73 | )
|
---|
74 | {
|
---|
75 | if (mKdTree) {
|
---|
76 | return mKdTree->CastRay(ray, instance);
|
---|
77 | }
|
---|
78 |
|
---|
79 | int faceIndex = 0;
|
---|
80 | int hits = 0;
|
---|
81 | float nearestT = MAX_FLOAT;
|
---|
82 | int nearestFace = -1;
|
---|
83 |
|
---|
84 | if (ray.GetType() == Ray::LOCAL_RAY && ray.intersections.size())
|
---|
85 | nearestT = ray.intersections[0].mT;
|
---|
86 |
|
---|
87 | for ( ;
|
---|
88 | faceIndex < mFaces.size();
|
---|
89 | faceIndex++) {
|
---|
90 | hits += CastRayToFace(faceIndex, ray, nearestT, nearestFace, instance);
|
---|
91 | if (mIsConvex && nearestFace != -1)
|
---|
92 | break;
|
---|
93 | }
|
---|
94 |
|
---|
95 | if ( hits && ray.GetType() == Ray::LOCAL_RAY ) {
|
---|
96 | if (ray.intersections.size())
|
---|
97 | ray.intersections[0] = Ray::RayIntersection(nearestT, instance, nearestFace);
|
---|
98 | else
|
---|
99 | ray.intersections.push_back(Ray::RayIntersection(nearestT, instance, nearestFace));
|
---|
100 | }
|
---|
101 |
|
---|
102 | return hits;
|
---|
103 | }
|
---|
104 |
|
---|
105 | int
|
---|
106 | Mesh::CastRayToSelectedFaces(
|
---|
107 | Ray &ray,
|
---|
108 | const vector<int> &faces,
|
---|
109 | MeshInstance *instance
|
---|
110 | )
|
---|
111 | {
|
---|
112 | vector<int>::const_iterator fi;
|
---|
113 | int faceIndex = 0;
|
---|
114 | int hits = 0;
|
---|
115 | float nearestT = MAX_FLOAT;
|
---|
116 | int nearestFace = -1;
|
---|
117 |
|
---|
118 | if (ray.GetType() == Ray::LOCAL_RAY && ray.intersections.size())
|
---|
119 | nearestT = ray.intersections[0].mT;
|
---|
120 |
|
---|
121 | for ( fi = faces.begin();
|
---|
122 | fi != faces.end();
|
---|
123 | fi++) {
|
---|
124 | hits += CastRayToFace(*fi, ray, nearestT, nearestFace, instance);
|
---|
125 | if (mIsConvex && nearestFace != -1)
|
---|
126 | break;
|
---|
127 | }
|
---|
128 |
|
---|
129 | if ( hits && ray.GetType() == Ray::LOCAL_RAY ) {
|
---|
130 | if (ray.intersections.size())
|
---|
131 | ray.intersections[0] = Ray::RayIntersection(nearestT, instance, nearestFace);
|
---|
132 | else
|
---|
133 | ray.intersections.push_back(Ray::RayIntersection(nearestT, instance, nearestFace));
|
---|
134 | }
|
---|
135 |
|
---|
136 | return hits;
|
---|
137 | }
|
---|
138 |
|
---|
139 |
|
---|
140 | // int_lineseg returns 1 if the given line segment intersects a 2D
|
---|
141 | // ray travelling in the positive X direction. This is used in the
|
---|
142 | // Jordan curve computation for polygon intersection.
|
---|
143 | inline int
|
---|
144 | int_lineseg(float px,
|
---|
145 | float py,
|
---|
146 | float u1,
|
---|
147 | float v1,
|
---|
148 | float u2,
|
---|
149 | float v2)
|
---|
150 | {
|
---|
151 | float t;
|
---|
152 | float ydiff;
|
---|
153 |
|
---|
154 | u1 -= px; u2 -= px; // translate line
|
---|
155 | v1 -= py; v2 -= py;
|
---|
156 |
|
---|
157 | if ((v1 > 0 && v2 > 0) ||
|
---|
158 | (v1 < 0 && v2 < 0) ||
|
---|
159 | (u1 < 0 && u2 < 0))
|
---|
160 | return 0;
|
---|
161 |
|
---|
162 | if (u1 > 0 && u2 > 0)
|
---|
163 | return 1;
|
---|
164 |
|
---|
165 | ydiff = v2 - v1;
|
---|
166 | if (fabs(ydiff) < Limits::Small) { // denominator near 0
|
---|
167 | if (((fabs(v1) > Limits::Small) ||
|
---|
168 | (u1 > 0) || (u2 > 0)))
|
---|
169 | return 0;
|
---|
170 | return 1;
|
---|
171 | }
|
---|
172 |
|
---|
173 | t = -v1 / ydiff; // Compute parameter
|
---|
174 |
|
---|
175 | return (u1 + t * (u2 - u1)) > 0;
|
---|
176 | }
|
---|
177 |
|
---|
178 |
|
---|
179 |
|
---|
180 | // intersection with the polygonal face of the mesh
|
---|
181 | int
|
---|
182 | Mesh::RayFaceIntersection(const int faceIndex,
|
---|
183 | const Ray &ray,
|
---|
184 | float &t,
|
---|
185 | const float nearestT
|
---|
186 | )
|
---|
187 | {
|
---|
188 | Face *face = mFaces[faceIndex];
|
---|
189 |
|
---|
190 | Plane3 plane = GetFacePlane(faceIndex);
|
---|
191 | float dot = DotProd(plane.mNormal, ray.GetDir());
|
---|
192 |
|
---|
193 | // Watch for near-zero denominator
|
---|
194 | // ONLY single sided polygons!!!!!
|
---|
195 | if (dot > -Limits::Small)
|
---|
196 | // if (fabs(dot) < Limits::Small)
|
---|
197 | return Ray::NO_INTERSECTION;
|
---|
198 |
|
---|
199 | t = (-plane.mD - DotProd(plane.mNormal, ray.GetLoc())) / dot;
|
---|
200 |
|
---|
201 | if (t <= Limits::Small)
|
---|
202 | return Ray::INTERSECTION_OUT_OF_LIMITS;
|
---|
203 |
|
---|
204 | if (t >= nearestT) {
|
---|
205 | return Ray::INTERSECTION_OUT_OF_LIMITS; // no intersection was found
|
---|
206 | }
|
---|
207 |
|
---|
208 | int count = 0;
|
---|
209 | float u, v, u1, v1, u2, v2;
|
---|
210 | int i;
|
---|
211 |
|
---|
212 | int paxis = plane.mNormal.DrivingAxis();
|
---|
213 |
|
---|
214 | // Project the intersection point onto the coordinate plane
|
---|
215 | // specified by which.
|
---|
216 | ray.Extrap(t).ExtractVerts(&u, &v, paxis);
|
---|
217 |
|
---|
218 |
|
---|
219 | int size = face->mVertexIndices.size();
|
---|
220 |
|
---|
221 | mVertices[face->mVertexIndices[size - 1]].
|
---|
222 | ExtractVerts(&u1, &v1, paxis );
|
---|
223 |
|
---|
224 | if (0 && size <= 4) {
|
---|
225 | // assume a convex face
|
---|
226 | for (i = 0; i < size; i++) {
|
---|
227 | mVertices[face->mVertexIndices[i]].ExtractVerts(&u2, &v2, paxis);
|
---|
228 | // line u1, v1, u2, v2
|
---|
229 | if ((v2 - v1)*(u1 - u) > (u2 - u1)*(v1 - v))
|
---|
230 | return Ray::NO_INTERSECTION;
|
---|
231 | u1 = u2;
|
---|
232 | v1 = v2;
|
---|
233 | }
|
---|
234 |
|
---|
235 | return Ray::INTERSECTION;
|
---|
236 | }
|
---|
237 |
|
---|
238 | // We're stuck with the Jordan curve computation. Count number
|
---|
239 | // of intersections between the line segments the polygon comprises
|
---|
240 | // with a ray originating at the point of intersection and
|
---|
241 | // travelling in the positive X direction.
|
---|
242 | for (i = 0; i < size; i++) {
|
---|
243 | mVertices[face->mVertexIndices[i]].ExtractVerts(&u2, &v2, paxis);
|
---|
244 | count += (int_lineseg(u, v, u1, v1, u2, v2) != 0);
|
---|
245 | u1 = u2;
|
---|
246 | v1 = v2;
|
---|
247 | }
|
---|
248 |
|
---|
249 | // We hit polygon if number of intersections is odd.
|
---|
250 | return (count & 1) ? Ray::INTERSECTION : Ray::NO_INTERSECTION;
|
---|
251 | }
|
---|
252 |
|
---|
253 |
|
---|
254 | int
|
---|
255 | MeshInstance::CastRay(
|
---|
256 | Ray &ray
|
---|
257 | )
|
---|
258 | {
|
---|
259 | int res = mMesh->CastRay(ray, this);
|
---|
260 | return res;
|
---|
261 | }
|
---|
262 |
|
---|
263 | int
|
---|
264 | MeshInstance::CastRay(
|
---|
265 | Ray &ray,
|
---|
266 | const vector<int> &faces
|
---|
267 | )
|
---|
268 | {
|
---|
269 | return mMesh->CastRayToSelectedFaces(ray, faces, this);
|
---|
270 | }
|
---|
271 |
|
---|
272 |
|
---|
273 | Plane3
|
---|
274 | Mesh::GetFacePlane(const int faceIndex)
|
---|
275 | {
|
---|
276 | Face *face = mFaces[faceIndex];
|
---|
277 | return Plane3(mVertices[face->mVertexIndices[0]],
|
---|
278 | mVertices[face->mVertexIndices[1]],
|
---|
279 | mVertices[face->mVertexIndices[2]]);
|
---|
280 | }
|
---|
281 |
|
---|
282 | int
|
---|
283 | MeshTransformedInstance::CastRay(
|
---|
284 | Ray &ray
|
---|
285 | )
|
---|
286 | {
|
---|
287 | ray.ApplyTransform(Invert(mWorldTransform));
|
---|
288 | int res = mMesh->CastRay(ray, this);
|
---|
289 | ray.ApplyTransform(mWorldTransform);
|
---|
290 |
|
---|
291 | return res;
|
---|
292 | }
|
---|
293 |
|
---|