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annotate src/scene.cc @ 28:97cfd9675310

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trying to pass the kdtree to the kernel
author John Tsiombikas <nuclear@member.fsf.org>
date Sat, 21 Aug 2010 03:42:49 +0100
parents 8b2f2ad14ae7
children 353d80127627
rev   line source
John@15 1 #include <math.h>
nuclear@25 2 #include <float.h>
nuclear@26 3 #include <assert.h>
nuclear@22 4 #include "scene.h"
nuclear@27 5 #include "ogl.h"
nuclear@6 6
nuclear@26 7
nuclear@27 8 static void draw_kdtree(const KDNode *node, int level = 0);
nuclear@27 9 static bool build_kdtree(KDNode *kd, int level = 0);
nuclear@27 10 static float eval_cost(const std::list<const Face*> &faces, const AABBox &aabb, int axis, float par_sarea = 1.0);
nuclear@26 11 static void free_kdtree(KDNode *node);
nuclear@28 12 static void kdtree_gpu_flatten(KDNodeGPU *kdbuf, int idx, const KDNode *node, const Face *facebuf);
nuclear@27 13 static void print_item_counts(const KDNode *node, int level);
nuclear@26 14
nuclear@26 15
nuclear@26 16 static int accel_param[NUM_ACCEL_PARAMS] = {
nuclear@28 17 40, // max tree depth
nuclear@26 18 0, // max items per node (0 means ignore limit)
nuclear@26 19 5, // estimated traversal cost
nuclear@26 20 15 // estimated interseciton cost
nuclear@26 21 };
nuclear@26 22
nuclear@26 23
nuclear@26 24 void set_accel_param(int p, int v)
nuclear@26 25 {
nuclear@26 26 assert(p >= 0 && p < NUM_ACCEL_PARAMS);
nuclear@26 27 accel_param[p] = v;
nuclear@26 28 }
nuclear@26 29
nuclear@26 30
John@15 31 #define FEQ(a, b) (fabs((a) - (b)) < 1e-8)
John@15 32 bool Face::operator ==(const Face &f) const
John@15 33 {
John@15 34 for(int i=0; i<3; i++) {
John@15 35 for(int j=0; j<3; j++) {
John@15 36 if(!FEQ(v[i].pos[j], f.v[i].pos[j])) {
John@15 37 return false;
John@15 38 }
John@15 39 if(!FEQ(v[i].normal[j], f.v[i].normal[j])) {
John@15 40 return false;
John@15 41 }
John@15 42 }
John@15 43 if(!FEQ(normal[i], f.normal[i])) {
John@15 44 return false;
John@15 45 }
John@15 46 }
John@15 47 return true;
John@15 48 }
John@15 49
nuclear@25 50 float AABBox::calc_surface_area() const
nuclear@25 51 {
nuclear@25 52 float area1 = (max[0] - min[0]) * (max[1] - min[1]);
nuclear@25 53 float area2 = (max[3] - min[3]) * (max[1] - min[1]);
nuclear@25 54 float area3 = (max[0] - min[0]) * (max[3] - min[3]);
nuclear@25 55
nuclear@25 56 return 2.0f * (area1 + area2 + area3);
nuclear@25 57 }
nuclear@25 58
nuclear@26 59 KDNode::KDNode()
nuclear@26 60 {
nuclear@26 61 axis = 0;
nuclear@26 62 pt = 0.0;
nuclear@26 63 left = right = 0;
nuclear@26 64 num_faces = 0;
nuclear@26 65 }
nuclear@26 66
nuclear@25 67
nuclear@24 68 Scene::Scene()
nuclear@24 69 {
nuclear@24 70 facebuf = 0;
nuclear@24 71 num_faces = -1;
nuclear@24 72 kdtree = 0;
nuclear@28 73 num_kdnodes = -1;
nuclear@28 74 kdbuf = 0;
nuclear@24 75 }
nuclear@24 76
nuclear@24 77 Scene::~Scene()
nuclear@24 78 {
nuclear@24 79 delete [] facebuf;
nuclear@28 80 delete [] kdbuf;
nuclear@28 81 free_kdtree(kdtree);
nuclear@24 82 }
nuclear@24 83
nuclear@13 84 bool Scene::add_mesh(Mesh *m)
nuclear@13 85 {
nuclear@13 86 // make sure triangles have material ids
nuclear@13 87 for(size_t i=0; i<m->faces.size(); i++) {
nuclear@13 88 m->faces[i].matid = m->matid;
nuclear@13 89 }
nuclear@24 90
nuclear@24 91 try {
nuclear@24 92 meshes.push_back(m);
nuclear@24 93 }
nuclear@24 94 catch(...) {
nuclear@24 95 return false;
nuclear@24 96 }
nuclear@24 97
nuclear@24 98 // invalidate facebuffer and count
nuclear@24 99 delete [] facebuf;
nuclear@24 100 facebuf = 0;
nuclear@24 101 num_faces = -1;
nuclear@24 102
nuclear@13 103 return true;
nuclear@13 104 }
nuclear@13 105
John@14 106 int Scene::get_num_meshes() const
John@14 107 {
John@14 108 return (int)meshes.size();
John@14 109 }
John@14 110
nuclear@13 111 int Scene::get_num_faces() const
nuclear@13 112 {
nuclear@24 113 if(num_faces >= 0) {
nuclear@24 114 return num_faces;
nuclear@24 115 }
nuclear@24 116
nuclear@24 117 num_faces = 0;
nuclear@13 118 for(size_t i=0; i<meshes.size(); i++) {
nuclear@13 119 num_faces += meshes[i]->faces.size();
nuclear@13 120 }
nuclear@13 121 return num_faces;
nuclear@13 122 }
nuclear@13 123
John@14 124 int Scene::get_num_materials() const
John@14 125 {
John@14 126 return (int)matlib.size();
John@14 127 }
John@14 128
John@14 129 Material *Scene::get_materials()
John@14 130 {
John@14 131 if(matlib.empty()) {
John@14 132 return 0;
John@14 133 }
John@14 134 return &matlib[0];
John@14 135 }
John@14 136
John@14 137 const Material *Scene::get_materials() const
John@14 138 {
John@14 139 if(matlib.empty()) {
John@14 140 return 0;
John@14 141 }
John@14 142 return &matlib[0];
John@14 143 }
nuclear@24 144
nuclear@24 145 const Face *Scene::get_face_buffer() const
nuclear@24 146 {
nuclear@24 147 if(facebuf) {
nuclear@24 148 return facebuf;
nuclear@24 149 }
nuclear@24 150
nuclear@24 151 int num_meshes = get_num_meshes();
nuclear@24 152
nuclear@24 153 printf("constructing face buffer with %d faces (out of %d meshes)\n", get_num_faces(), num_meshes);
nuclear@24 154 facebuf = new Face[num_faces];
nuclear@24 155 Face *fptr = facebuf;
nuclear@24 156
nuclear@24 157 for(int i=0; i<num_meshes; i++) {
nuclear@24 158 for(size_t j=0; j<meshes[i]->faces.size(); j++) {
nuclear@24 159 *fptr++ = meshes[i]->faces[j];
nuclear@24 160 }
nuclear@24 161 }
nuclear@24 162 return facebuf;
nuclear@24 163 }
nuclear@24 164
nuclear@28 165 const KDNodeGPU *Scene::get_kdtree_buffer() const
nuclear@28 166 {
nuclear@28 167 if(kdbuf) {
nuclear@28 168 return kdbuf;
nuclear@28 169 }
nuclear@28 170
nuclear@28 171 if(!kdtree) {
nuclear@28 172 ((Scene*)this)->build_kdtree();
nuclear@28 173 }
nuclear@28 174
nuclear@28 175 if(!get_num_kdnodes()) {
nuclear@28 176 return 0;
nuclear@28 177 }
nuclear@28 178
nuclear@28 179 kdbuf = new KDNodeGPU[num_kdnodes + 1];
nuclear@28 180 kdtree_gpu_flatten(kdbuf, 1, kdtree, get_face_buffer());
nuclear@28 181 return kdbuf;
nuclear@28 182 }
nuclear@28 183
nuclear@28 184 int Scene::get_num_kdnodes() const
nuclear@28 185 {
nuclear@28 186 if(num_kdnodes >= 0) {
nuclear@28 187 return num_kdnodes;
nuclear@28 188 }
nuclear@28 189
nuclear@28 190 num_kdnodes = kdtree_nodes(kdtree);
nuclear@28 191 return num_kdnodes;
nuclear@28 192 }
nuclear@28 193
nuclear@24 194
nuclear@27 195 void Scene::draw_kdtree() const
nuclear@27 196 {
nuclear@27 197 glPushAttrib(GL_ENABLE_BIT);
nuclear@27 198 glDisable(GL_LIGHTING);
nuclear@27 199 glDepthMask(0);
nuclear@27 200
nuclear@27 201 glBegin(GL_LINES);
nuclear@27 202 ::draw_kdtree(kdtree, 0);
nuclear@27 203 glEnd();
nuclear@27 204
nuclear@27 205 glDepthMask(1);
nuclear@27 206 glPopAttrib();
nuclear@27 207 }
nuclear@27 208
nuclear@27 209 static float palette[][3] = {
nuclear@27 210 {0, 1, 0},
nuclear@27 211 {1, 0, 0},
nuclear@27 212 {0, 0, 1},
nuclear@27 213 {1, 1, 0},
nuclear@27 214 {0, 0, 1},
nuclear@27 215 {1, 0, 1}
nuclear@27 216 };
nuclear@27 217 static int pal_size = sizeof palette / sizeof *palette;
nuclear@27 218
nuclear@27 219 static void draw_kdtree(const KDNode *node, int level)
nuclear@27 220 {
nuclear@27 221 if(!node) return;
nuclear@27 222
nuclear@27 223 draw_kdtree(node->left, level + 1);
nuclear@27 224 draw_kdtree(node->right, level + 1);
nuclear@27 225
nuclear@27 226 glColor3fv(palette[level % pal_size]);
nuclear@27 227
nuclear@27 228 glVertex3fv(node->aabb.min);
nuclear@27 229 glVertex3f(node->aabb.max[0], node->aabb.min[1], node->aabb.min[2]);
nuclear@27 230 glVertex3f(node->aabb.max[0], node->aabb.min[1], node->aabb.min[2]);
nuclear@27 231 glVertex3f(node->aabb.max[0], node->aabb.max[1], node->aabb.min[2]);
nuclear@27 232 glVertex3f(node->aabb.max[0], node->aabb.max[1], node->aabb.min[2]);
nuclear@27 233 glVertex3f(node->aabb.min[0], node->aabb.max[1], node->aabb.min[2]);
nuclear@27 234 glVertex3f(node->aabb.min[0], node->aabb.max[1], node->aabb.min[2]);
nuclear@27 235 glVertex3fv(node->aabb.min);
nuclear@27 236
nuclear@27 237 glVertex3f(node->aabb.min[0], node->aabb.min[1], node->aabb.max[2]);
nuclear@27 238 glVertex3f(node->aabb.max[0], node->aabb.min[1], node->aabb.max[2]);
nuclear@27 239 glVertex3f(node->aabb.max[0], node->aabb.min[1], node->aabb.max[2]);
nuclear@27 240 glVertex3fv(node->aabb.max);
nuclear@27 241 glVertex3fv(node->aabb.max);
nuclear@27 242 glVertex3f(node->aabb.min[0], node->aabb.max[1], node->aabb.max[2]);
nuclear@27 243 glVertex3f(node->aabb.min[0], node->aabb.max[1], node->aabb.max[2]);
nuclear@27 244 glVertex3f(node->aabb.min[0], node->aabb.min[1], node->aabb.max[2]);
nuclear@27 245
nuclear@27 246 glVertex3fv(node->aabb.min);
nuclear@27 247 glVertex3f(node->aabb.min[0], node->aabb.min[1], node->aabb.max[2]);
nuclear@27 248 glVertex3f(node->aabb.max[0], node->aabb.min[1], node->aabb.min[2]);
nuclear@27 249 glVertex3f(node->aabb.max[0], node->aabb.min[1], node->aabb.max[2]);
nuclear@27 250 glVertex3f(node->aabb.max[0], node->aabb.max[1], node->aabb.min[2]);
nuclear@27 251 glVertex3fv(node->aabb.max);
nuclear@27 252 glVertex3f(node->aabb.min[0], node->aabb.max[1], node->aabb.min[2]);
nuclear@27 253 glVertex3f(node->aabb.min[0], node->aabb.max[1], node->aabb.max[2]);
nuclear@27 254 }
nuclear@27 255
nuclear@27 256 bool Scene::build_kdtree()
nuclear@24 257 {
nuclear@24 258 const Face *faces = get_face_buffer();
nuclear@24 259 int num_faces = get_num_faces();
nuclear@24 260
nuclear@25 261 printf("Constructing kd-tree out of %d faces ...\n", num_faces);
nuclear@25 262
nuclear@27 263 int icost = accel_param[ACCEL_PARAM_COST_INTERSECT];
nuclear@27 264 int tcost = accel_param[ACCEL_PARAM_COST_TRAVERSE];
nuclear@27 265 printf(" max items per leaf: %d\n", accel_param[ACCEL_PARAM_MAX_NODE_ITEMS]);
nuclear@27 266 printf(" SAH parameters - tcost: %d - icost: %d\n", tcost, icost);
nuclear@27 267
nuclear@25 268 free_kdtree(kdtree);
nuclear@25 269 kdtree = new KDNode;
nuclear@25 270
nuclear@25 271 /* Start the construction of the kdtree by adding all faces of the scene
nuclear@25 272 * to the new root node. At the same time calculate the root's AABB.
nuclear@25 273 */
nuclear@25 274 kdtree->aabb.min[0] = kdtree->aabb.min[1] = kdtree->aabb.min[2] = FLT_MAX;
nuclear@25 275 kdtree->aabb.max[0] = kdtree->aabb.max[1] = kdtree->aabb.max[2] = -FLT_MAX;
nuclear@25 276
nuclear@24 277 for(int i=0; i<num_faces; i++) {
nuclear@25 278 const Face *face = faces + i;
nuclear@25 279
nuclear@25 280 // for each vertex of the face ...
nuclear@25 281 for(int j=0; j<3; j++) {
nuclear@25 282 const float *pos = face->v[j].pos;
nuclear@25 283
nuclear@25 284 // for each element (xyz) of the position vector ...
nuclear@25 285 for(int k=0; k<3; k++) {
nuclear@25 286 if(pos[k] < kdtree->aabb.min[k]) {
nuclear@25 287 kdtree->aabb.min[k] = pos[k];
nuclear@25 288 }
nuclear@25 289 if(pos[k] > kdtree->aabb.max[k]) {
nuclear@25 290 kdtree->aabb.max[k] = pos[k];
nuclear@25 291 }
nuclear@25 292 }
nuclear@25 293 }
nuclear@25 294
nuclear@25 295 kdtree->faces.push_back(face); // add the face
nuclear@26 296 kdtree->num_faces++;
nuclear@24 297 }
nuclear@24 298
nuclear@26 299 // calculate the heuristic for the root
nuclear@26 300 kdtree->cost = eval_cost(kdtree->faces, kdtree->aabb, kdtree->axis);
nuclear@26 301
nuclear@25 302 // now proceed splitting the root recursively
nuclear@27 303 if(!::build_kdtree(kdtree)) {
nuclear@27 304 fprintf(stderr, "failed to build kdtree\n");
nuclear@27 305 return false;
nuclear@27 306 }
nuclear@27 307
nuclear@27 308 printf(" tree depth: %d\n", kdtree_depth(kdtree));
nuclear@27 309 print_item_counts(kdtree, 0);
nuclear@27 310 return true;
nuclear@24 311 }
nuclear@24 312
nuclear@27 313 static bool build_kdtree(KDNode *kd, int level)
nuclear@24 314 {
nuclear@28 315 int opt_max_depth = accel_param[ACCEL_PARAM_MAX_TREE_DEPTH];
nuclear@26 316 int opt_max_items = accel_param[ACCEL_PARAM_MAX_NODE_ITEMS];
nuclear@27 317 int tcost = accel_param[ACCEL_PARAM_COST_TRAVERSE];
nuclear@27 318
nuclear@28 319 if(kd->num_faces == 0 || level >= opt_max_depth) {
nuclear@27 320 return true;
nuclear@25 321 }
nuclear@25 322
nuclear@27 323 int axis = level % 3;
nuclear@27 324 //float parent_sa = kd->aabb.calc_surface_area();
nuclear@26 325
nuclear@26 326 float best_cost[2], best_sum_cost = FLT_MAX;
nuclear@26 327 float best_split;
nuclear@26 328
nuclear@26 329 std::list<const Face*>::iterator it = kd->faces.begin();
nuclear@26 330 while(it != kd->faces.end()) {
nuclear@26 331 const Face *face = *it++;
nuclear@26 332
nuclear@26 333 for(int i=0; i<3; i++) {
nuclear@26 334 AABBox aabb_left, aabb_right;
nuclear@26 335 const float *split = face->v[i].pos;
nuclear@26 336
nuclear@26 337 aabb_left = aabb_right = kd->aabb;
nuclear@26 338 aabb_left.max[axis] = split[axis];
nuclear@26 339 aabb_right.min[axis] = split[axis];
nuclear@26 340
nuclear@26 341 float left_cost = eval_cost(kd->faces, aabb_left, axis);
nuclear@26 342 float right_cost = eval_cost(kd->faces, aabb_right, axis);
nuclear@27 343 float sum_cost = left_cost + right_cost - tcost; // tcost is added twice
nuclear@26 344
nuclear@26 345 if(sum_cost < best_sum_cost) {
nuclear@26 346 best_cost[0] = left_cost;
nuclear@26 347 best_cost[1] = right_cost;
nuclear@26 348 best_sum_cost = sum_cost;
nuclear@26 349 best_split = split[axis];
nuclear@26 350 }
nuclear@26 351 }
nuclear@26 352 }
nuclear@26 353
nuclear@27 354 printf("current cost: %f, best_cost: %f\n", kd->cost, best_sum_cost);
nuclear@27 355 if(best_sum_cost > kd->cost && (opt_max_items == 0 || kd->num_faces <= opt_max_items)) {
nuclear@27 356 return true; // stop splitting if it doesn't reduce the cost
nuclear@26 357 }
nuclear@26 358 kd->pt = best_split;
nuclear@26 359
nuclear@26 360 // create the two children
nuclear@26 361 KDNode *kdleft, *kdright;
nuclear@26 362 kdleft = new KDNode;
nuclear@26 363 kdright = new KDNode;
nuclear@26 364
nuclear@26 365 kdleft->aabb = kdright->aabb = kd->aabb;
nuclear@26 366
nuclear@26 367 kdleft->aabb.max[axis] = best_split;
nuclear@26 368 kdright->aabb.min[axis] = best_split;
nuclear@26 369
nuclear@26 370 kdleft->cost = best_cost[0];
nuclear@26 371 kdright->cost = best_cost[1];
nuclear@26 372
nuclear@27 373 //kdleft->axis = kdright->axis = (axis + 1) % 3;
nuclear@27 374
nuclear@26 375 it = kd->faces.begin();
nuclear@26 376 while(it != kd->faces.end()) {
nuclear@26 377 const Face *face = *it++;
nuclear@26 378
nuclear@26 379 if(face->v[0].pos[axis] < best_split ||
nuclear@26 380 face->v[1].pos[axis] < best_split ||
nuclear@26 381 face->v[2].pos[axis] < best_split) {
nuclear@26 382 kdleft->faces.push_back(face);
nuclear@26 383 kdleft->num_faces++;
nuclear@26 384 }
nuclear@26 385 if(face->v[0].pos[axis] >= best_split ||
nuclear@26 386 face->v[1].pos[axis] >= best_split ||
nuclear@26 387 face->v[2].pos[axis] >= best_split) {
nuclear@26 388 kdright->faces.push_back(face);
nuclear@26 389 kdright->num_faces++;
nuclear@26 390 }
nuclear@26 391 }
nuclear@27 392 kd->faces.clear(); // only leaves have faces
nuclear@26 393
nuclear@26 394 kd->left = kdleft;
nuclear@26 395 kd->right = kdright;
nuclear@27 396
nuclear@27 397 return build_kdtree(kd->left, level + 1) && build_kdtree(kd->right, level + 1);
nuclear@26 398 }
nuclear@26 399
nuclear@27 400 static float eval_cost(const std::list<const Face*> &faces, const AABBox &aabb, int axis, float par_sarea)
nuclear@26 401 {
nuclear@26 402 int num_inside = 0;
nuclear@26 403 int tcost = accel_param[ACCEL_PARAM_COST_TRAVERSE];
nuclear@26 404 int icost = accel_param[ACCEL_PARAM_COST_INTERSECT];
nuclear@26 405
nuclear@26 406 std::list<const Face*>::const_iterator it = faces.begin();
nuclear@26 407 while(it != faces.end()) {
nuclear@26 408 const Face *face = *it++;
nuclear@26 409
nuclear@26 410 for(int i=0; i<3; i++) {
nuclear@26 411 if(face->v[i].pos[axis] >= aabb.min[axis] && face->v[i].pos[axis] < aabb.max[axis]) {
nuclear@26 412 num_inside++;
nuclear@26 413 break;
nuclear@26 414 }
nuclear@26 415 }
nuclear@26 416 }
nuclear@26 417
nuclear@27 418 float sarea = aabb.calc_surface_area();
nuclear@27 419 if(sarea < 1e-8) {
nuclear@27 420 return FLT_MAX; // heavily penalize 0-area voxels
nuclear@27 421 }
nuclear@27 422
nuclear@27 423 return tcost + (sarea / par_sarea) * num_inside * icost;
nuclear@24 424 }
nuclear@25 425
nuclear@25 426 static void free_kdtree(KDNode *node)
nuclear@25 427 {
nuclear@25 428 if(node) {
nuclear@25 429 free_kdtree(node->left);
nuclear@25 430 free_kdtree(node->right);
nuclear@25 431 delete node;
nuclear@25 432 }
nuclear@25 433 }
nuclear@27 434
nuclear@28 435 int kdtree_depth(const KDNode *node)
nuclear@27 436 {
nuclear@27 437 if(!node) return 0;
nuclear@27 438
nuclear@27 439 int left = kdtree_depth(node->left);
nuclear@27 440 int right = kdtree_depth(node->right);
nuclear@27 441 return (left > right ? left : right) + 1;
nuclear@27 442 }
nuclear@27 443
nuclear@28 444 int kdtree_nodes(const KDNode *node)
nuclear@28 445 {
nuclear@28 446 if(!node) return 0;
nuclear@28 447 return kdtree_nodes(node->left) + kdtree_nodes(node->right) + 1;
nuclear@28 448 }
nuclear@28 449
nuclear@28 450 #define MAX_FACES (sizeof dest->face_idx / sizeof *dest->face_idx)
nuclear@28 451 static void kdtree_gpu_flatten(KDNodeGPU *kdbuf, int idx, const KDNode *node, const Face *facebuf)
nuclear@28 452 {
nuclear@28 453 KDNodeGPU *dest = kdbuf + idx;
nuclear@28 454
nuclear@28 455 dest->aabb = node->aabb;
nuclear@28 456 dest->num_faces = 0;
nuclear@28 457
nuclear@28 458 std::list<const Face*>::const_iterator it = node->faces.begin();
nuclear@28 459 while(it != node->faces.end()) {
nuclear@28 460 if(dest->num_faces >= (int)MAX_FACES) {
nuclear@28 461 fprintf(stderr, "kdtree_gpu_flatten WARNING: more than %d faces in node, skipping!\n", (int)MAX_FACES);
nuclear@28 462 break;
nuclear@28 463 }
nuclear@28 464 dest->face_idx[dest->num_faces++] = *it - facebuf;
nuclear@28 465 }
nuclear@28 466
nuclear@28 467 if(node->left) {
nuclear@28 468 assert(node->right);
nuclear@28 469 kdtree_gpu_flatten(kdbuf, idx * 2, node->left, facebuf);
nuclear@28 470 kdtree_gpu_flatten(kdbuf, idx * 2 + 1, node->right, facebuf);
nuclear@28 471 }
nuclear@28 472 }
nuclear@28 473
nuclear@27 474 static void print_item_counts(const KDNode *node, int level)
nuclear@27 475 {
nuclear@27 476 if(!node) return;
nuclear@27 477
nuclear@27 478 for(int i=0; i<level; i++) {
nuclear@27 479 fputs(" ", stdout);
nuclear@27 480 }
nuclear@27 481 printf("- %d (cost: %f)\n", node->num_faces, node->cost);
nuclear@27 482
nuclear@27 483 print_item_counts(node->left, level + 1);
nuclear@27 484 print_item_counts(node->right, level + 1);
nuclear@27 485 }