clray

annotate rt.cl @ 47:30bf84881553

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added interactive controls for turning shadows/reflections on and off as well as selecting maximum ray tracing iterations
author John Tsiombikas <nuclear@member.fsf.org>
date Tue, 31 Aug 2010 01:47:27 +0100
parents 8047637961a2
children
rev   line source
nuclear@12 1 /* vim: set ft=opencl:ts=4:sw=4 */
nuclear@45 2 #include "common.h"
nuclear@12 3
nuclear@2 4 struct RendInfo {
nuclear@22 5 float4 ambient;
nuclear@2 6 int xsz, ysz;
nuclear@9 7 int num_faces, num_lights;
nuclear@2 8 int max_iter;
nuclear@47 9 int cast_shadows;
nuclear@2 10 };
nuclear@2 11
nuclear@9 12 struct Vertex {
nuclear@2 13 float4 pos;
nuclear@9 14 float4 normal;
nuclear@12 15 float4 tex;
nuclear@12 16 float4 padding;
nuclear@9 17 };
nuclear@9 18
nuclear@9 19 struct Face {
nuclear@9 20 struct Vertex v[3];
nuclear@9 21 float4 normal;
nuclear@9 22 int matid;
nuclear@12 23 int padding[3];
nuclear@9 24 };
nuclear@9 25
nuclear@9 26 struct Material {
nuclear@5 27 float4 kd, ks;
nuclear@9 28 float kr, kt;
nuclear@9 29 float spow;
nuclear@12 30 float padding;
nuclear@2 31 };
nuclear@2 32
nuclear@3 33 struct Light {
nuclear@3 34 float4 pos, color;
nuclear@3 35 };
nuclear@3 36
nuclear@2 37 struct Ray {
nuclear@2 38 float4 origin, dir;
nuclear@2 39 };
nuclear@2 40
nuclear@2 41 struct SurfPoint {
nuclear@2 42 float t;
nuclear@12 43 float4 pos, norm, dbg;
nuclear@9 44 global const struct Face *obj;
nuclear@19 45 struct Material mat;
nuclear@2 46 };
nuclear@2 47
nuclear@16 48 struct Scene {
nuclear@16 49 float4 ambient;
nuclear@16 50 global const struct Face *faces;
nuclear@16 51 int num_faces;
nuclear@16 52 global const struct Light *lights;
nuclear@16 53 int num_lights;
nuclear@16 54 global const struct Material *matlib;
nuclear@43 55 //global const struct KDNode *kdtree;
nuclear@47 56 bool cast_shadows;
nuclear@28 57 };
nuclear@28 58
nuclear@28 59 struct AABBox {
nuclear@28 60 float4 min, max;
nuclear@28 61 };
nuclear@28 62
nuclear@28 63 struct KDNode {
nuclear@29 64 struct AABBox aabb;
nuclear@43 65 int face_idx[MAX_NODE_FACES];
nuclear@28 66 int num_faces;
nuclear@35 67 int left, right;
nuclear@35 68 int padding;
nuclear@16 69 };
nuclear@2 70
nuclear@16 71 #define MIN_ENERGY 0.001
nuclear@21 72 #define EPSILON 1e-5
nuclear@16 73
nuclear@43 74 float4 shade(struct Ray ray, struct Scene *scn, const struct SurfPoint *sp, read_only image2d_t kdimg);
nuclear@43 75 bool find_intersection(struct Ray ray, const struct Scene *scn, struct SurfPoint *sp, read_only image2d_t kdimg);
nuclear@9 76 bool intersect(struct Ray ray, global const struct Face *face, struct SurfPoint *sp);
nuclear@28 77 bool intersect_aabb(struct Ray ray, struct AABBox aabb);
nuclear@16 78
nuclear@8 79 float4 reflect(float4 v, float4 n);
nuclear@8 80 float4 transform(float4 v, global const float *xform);
nuclear@16 81 void transform_ray(struct Ray *ray, global const float *xform, global const float *invtrans);
nuclear@12 82 float4 calc_bary(float4 pt, global const struct Face *face, float4 norm);
nuclear@19 83 float mean(float4 v);
nuclear@4 84
nuclear@43 85 void read_kdnode(int idx, struct KDNode *node, read_only image2d_t kdimg);
nuclear@43 86
nuclear@39 87
nuclear@39 88 kernel void render(write_only image2d_t fb,
nuclear@4 89 global const struct RendInfo *rinf,
nuclear@9 90 global const struct Face *faces,
nuclear@9 91 global const struct Material *matlib,
nuclear@4 92 global const struct Light *lights,
nuclear@7 93 global const struct Ray *primrays,
nuclear@12 94 global const float *xform,
nuclear@28 95 global const float *invtrans,
nuclear@43 96 //global const struct KDNode *kdtree
nuclear@43 97 read_only image2d_t kdtree_img)
nuclear@2 98 {
nuclear@2 99 int idx = get_global_id(0);
nuclear@2 100
nuclear@16 101 struct Scene scn;
nuclear@16 102 scn.ambient = rinf->ambient;
nuclear@16 103 scn.faces = faces;
nuclear@16 104 scn.num_faces = rinf->num_faces;
nuclear@16 105 scn.lights = lights;
nuclear@16 106 scn.num_lights = rinf->num_lights;
nuclear@16 107 scn.matlib = matlib;
nuclear@47 108 scn.cast_shadows = rinf->cast_shadows;
nuclear@8 109
nuclear@16 110 struct Ray ray = primrays[idx];
nuclear@16 111 transform_ray(&ray, xform, invtrans);
nuclear@4 112
nuclear@19 113 float4 pixel = (float4)(0, 0, 0, 0);
nuclear@22 114 float4 energy = (float4)(1.0, 1.0, 1.0, 0.0);
nuclear@19 115 int iter = 0;
nuclear@19 116
nuclear@47 117 while(iter++ <= rinf->max_iter && mean(energy) > MIN_ENERGY) {
nuclear@19 118 struct SurfPoint sp;
nuclear@43 119 if(find_intersection(ray, &scn, &sp, kdtree_img)) {
nuclear@43 120 pixel += shade(ray, &scn, &sp, kdtree_img) * energy;
nuclear@19 121
nuclear@19 122 float4 refl_col = sp.mat.ks * sp.mat.kr;
nuclear@19 123
nuclear@19 124 ray.origin = sp.pos;
nuclear@19 125 ray.dir = reflect(-ray.dir, sp.norm);
nuclear@19 126
nuclear@35 127 energy *= refl_col;
nuclear@19 128 } else {
nuclear@43 129 energy = (float4)(0.0, 0.0, 0.0, 0.0);
nuclear@19 130 }
nuclear@17 131 }
nuclear@19 132
nuclear@39 133 int2 coord;
nuclear@43 134 coord.x = idx % rinf->xsz;
nuclear@43 135 coord.y = idx / rinf->xsz;
nuclear@39 136
nuclear@39 137 write_imagef(fb, coord, pixel);
nuclear@4 138 }
nuclear@4 139
nuclear@43 140 float4 shade(struct Ray ray, struct Scene *scn, const struct SurfPoint *sp, read_only image2d_t kdimg)
nuclear@16 141 {
nuclear@16 142 float4 norm = sp->norm;
nuclear@43 143 //bool entering = true;
nuclear@12 144
nuclear@12 145 if(dot(ray.dir, norm) >= 0.0) {
nuclear@12 146 norm = -norm;
nuclear@43 147 //entering = false;
nuclear@12 148 }
nuclear@12 149
nuclear@19 150 float4 dcol = scn->ambient * sp->mat.kd;
nuclear@8 151 float4 scol = (float4)(0, 0, 0, 0);
nuclear@5 152
nuclear@16 153 for(int i=0; i<scn->num_lights; i++) {
nuclear@16 154 float4 ldir = scn->lights[i].pos - sp->pos;
nuclear@5 155
nuclear@16 156 struct Ray shadowray;
nuclear@16 157 shadowray.origin = sp->pos;
nuclear@16 158 shadowray.dir = ldir;
nuclear@5 159
nuclear@47 160 if(!scn->cast_shadows || !find_intersection(shadowray, scn, 0, kdimg)) {
nuclear@16 161 ldir = normalize(ldir);
nuclear@43 162 float4 vdir = -ray.dir;
nuclear@43 163 vdir.x = native_divide(vdir.x, RAY_MAG);
nuclear@43 164 vdir.y = native_divide(vdir.y, RAY_MAG);
nuclear@43 165 vdir.z = native_divide(vdir.z, RAY_MAG);
nuclear@16 166 float4 vref = reflect(vdir, norm);
nuclear@16 167
nuclear@16 168 float diff = fmax(dot(ldir, norm), 0.0f);
nuclear@43 169 dcol += sp->mat.kd /* scn->lights[i].color*/ * diff;
nuclear@16 170
nuclear@43 171 float spec = native_powr(fmax(dot(ldir, vref), 0.0f), sp->mat.spow);
nuclear@43 172 scol += sp->mat.ks /* scn->lights[i].color*/ * spec;
nuclear@16 173 }
nuclear@16 174 }
nuclear@16 175
nuclear@8 176 return dcol + scol;
nuclear@2 177 }
nuclear@2 178
nuclear@45 179 #define STACK_SIZE MAX_TREE_DEPTH
nuclear@43 180 bool find_intersection(struct Ray ray, const struct Scene *scn, struct SurfPoint *spres, read_only image2d_t kdimg)
nuclear@28 181 {
nuclear@29 182 struct SurfPoint sp0;
nuclear@29 183 sp0.t = 1.0;
nuclear@29 184 sp0.obj = 0;
nuclear@29 185
nuclear@29 186 int idxstack[STACK_SIZE];
nuclear@31 187 int top = 0; // points after the topmost element of the stack
nuclear@35 188 idxstack[top++] = 0; // root at tree[0]
nuclear@29 189
nuclear@31 190 while(top > 0) {
nuclear@31 191 int idx = idxstack[--top]; // remove this index from the stack and process it
nuclear@30 192
nuclear@43 193 struct KDNode node;
nuclear@43 194 read_kdnode(idx, &node, kdimg);
nuclear@29 195
nuclear@43 196 if(intersect_aabb(ray, node.aabb)) {
nuclear@43 197 if(node.left == -1) {
nuclear@31 198 // leaf node... check each face in turn and update the nearest intersection as needed
nuclear@43 199 for(int i=0; i<node.num_faces; i++) {
nuclear@31 200 struct SurfPoint spt;
nuclear@43 201 int fidx = node.face_idx[i];
nuclear@29 202
nuclear@31 203 if(intersect(ray, scn->faces + fidx, &spt) && spt.t < sp0.t) {
nuclear@31 204 sp0 = spt;
nuclear@29 205 }
nuclear@29 206 }
nuclear@31 207 } else {
nuclear@31 208 // internal node... recurse to the children
nuclear@43 209 idxstack[top++] = node.left;
nuclear@43 210 idxstack[top++] = node.right;
nuclear@29 211 }
nuclear@29 212 }
nuclear@29 213 }
nuclear@29 214
nuclear@29 215 if(!sp0.obj) {
nuclear@29 216 return false;
nuclear@29 217 }
nuclear@29 218
nuclear@29 219 if(spres) {
nuclear@29 220 *spres = sp0;
nuclear@29 221 spres->mat = scn->matlib[sp0.obj->matid];
nuclear@29 222 }
nuclear@29 223 return true;
nuclear@28 224 }
nuclear@16 225
nuclear@16 226 bool intersect(struct Ray ray, global const struct Face *face, struct SurfPoint *sp)
nuclear@2 227 {
nuclear@12 228 float4 origin = ray.origin;
nuclear@12 229 float4 dir = ray.dir;
nuclear@12 230 float4 norm = face->normal;
nuclear@12 231
nuclear@16 232 float ndotdir = dot(dir, norm);
nuclear@12 233
nuclear@9 234 if(fabs(ndotdir) <= EPSILON) {
nuclear@9 235 return false;
nuclear@9 236 }
nuclear@2 237
nuclear@9 238 float4 pt = face->v[0].pos;
nuclear@12 239 float4 vec = pt - origin;
nuclear@2 240
nuclear@16 241 float ndotvec = dot(norm, vec);
nuclear@43 242 float t = native_divide(ndotvec, ndotdir);
nuclear@2 243
nuclear@2 244 if(t < EPSILON || t > 1.0) {
nuclear@2 245 return false;
nuclear@2 246 }
nuclear@12 247 pt = origin + dir * t;
nuclear@9 248
nuclear@12 249
nuclear@12 250 float4 bc = calc_bary(pt, face, norm);
nuclear@9 251 float bc_sum = bc.x + bc.y + bc.z;
nuclear@9 252
nuclear@20 253 if(bc_sum < 1.0 - EPSILON || bc_sum > 1.0 + EPSILON) {
nuclear@9 254 return false;
nuclear@12 255 bc *= 1.2;
nuclear@9 256 }
nuclear@2 257
nuclear@2 258 sp->t = t;
nuclear@9 259 sp->pos = pt;
nuclear@21 260 sp->norm = normalize(face->v[0].normal * bc.x + face->v[1].normal * bc.y + face->v[2].normal * bc.z);
nuclear@9 261 sp->obj = face;
nuclear@12 262 sp->dbg = bc;
nuclear@2 263 return true;
nuclear@2 264 }
nuclear@5 265
nuclear@28 266 bool intersect_aabb(struct Ray ray, struct AABBox aabb)
nuclear@28 267 {
nuclear@28 268 if(ray.origin.x >= aabb.min.x && ray.origin.y >= aabb.min.y && ray.origin.z >= aabb.min.z &&
nuclear@28 269 ray.origin.x < aabb.max.x && ray.origin.y < aabb.max.y && ray.origin.z < aabb.max.z) {
nuclear@28 270 return true;
nuclear@28 271 }
nuclear@28 272
nuclear@29 273 float4 bbox[2] = {
nuclear@29 274 aabb.min.x, aabb.min.y, aabb.min.z, 0,
nuclear@29 275 aabb.max.x, aabb.max.y, aabb.max.z, 0
nuclear@29 276 };
nuclear@28 277
nuclear@28 278 int xsign = (int)(ray.dir.x < 0.0);
nuclear@43 279 float invdirx = native_recip(ray.dir.x);
nuclear@28 280 float tmin = (bbox[xsign].x - ray.origin.x) * invdirx;
nuclear@28 281 float tmax = (bbox[1 - xsign].x - ray.origin.x) * invdirx;
nuclear@28 282
nuclear@28 283 int ysign = (int)(ray.dir.y < 0.0);
nuclear@43 284 float invdiry = native_recip(ray.dir.y);
nuclear@28 285 float tymin = (bbox[ysign].y - ray.origin.y) * invdiry;
nuclear@28 286 float tymax = (bbox[1 - ysign].y - ray.origin.y) * invdiry;
nuclear@28 287
nuclear@28 288 if(tmin > tymax || tymin > tmax) {
nuclear@28 289 return false;
nuclear@28 290 }
nuclear@28 291
nuclear@28 292 if(tymin > tmin) tmin = tymin;
nuclear@28 293 if(tymax < tmax) tmax = tymax;
nuclear@28 294
nuclear@28 295 int zsign = (int)(ray.dir.z < 0.0);
nuclear@43 296 float invdirz = native_recip(ray.dir.z);
nuclear@28 297 float tzmin = (bbox[zsign].z - ray.origin.z) * invdirz;
nuclear@28 298 float tzmax = (bbox[1 - zsign].z - ray.origin.z) * invdirz;
nuclear@28 299
nuclear@28 300 if(tmin > tzmax || tzmin > tmax) {
nuclear@28 301 return false;
nuclear@28 302 }
nuclear@28 303
nuclear@29 304 return tmin < 1.0 && tmax > 0.0;
nuclear@28 305 }
nuclear@28 306
nuclear@8 307 float4 reflect(float4 v, float4 n)
nuclear@5 308 {
nuclear@23 309 return 2.0f * dot(v, n) * n - v;
nuclear@5 310 }
nuclear@8 311
nuclear@8 312 float4 transform(float4 v, global const float *xform)
nuclear@8 313 {
nuclear@8 314 float4 res;
nuclear@8 315 res.x = v.x * xform[0] + v.y * xform[4] + v.z * xform[8] + xform[12];
nuclear@8 316 res.y = v.x * xform[1] + v.y * xform[5] + v.z * xform[9] + xform[13];
nuclear@8 317 res.z = v.x * xform[2] + v.y * xform[6] + v.z * xform[10] + xform[14];
nuclear@12 318 res.w = 0.0;
nuclear@8 319 return res;
nuclear@8 320 }
nuclear@8 321
nuclear@16 322 void transform_ray(struct Ray *ray, global const float *xform, global const float *invtrans)
nuclear@8 323 {
nuclear@16 324 ray->origin = transform(ray->origin, xform);
nuclear@16 325 ray->dir = transform(ray->dir, invtrans);
nuclear@8 326 }
nuclear@9 327
nuclear@12 328 float4 calc_bary(float4 pt, global const struct Face *face, float4 norm)
nuclear@9 329 {
nuclear@12 330 float4 bc = (float4)(0, 0, 0, 0);
nuclear@9 331
nuclear@12 332 // calculate area of the whole triangle
nuclear@12 333 float4 v1 = face->v[1].pos - face->v[0].pos;
nuclear@12 334 float4 v2 = face->v[2].pos - face->v[0].pos;
nuclear@12 335 float4 xv1v2 = cross(v1, v2);
nuclear@12 336
nuclear@16 337 float area = fabs(dot(xv1v2, norm)) * 0.5;
nuclear@9 338 if(area < EPSILON) {
nuclear@9 339 return bc;
nuclear@9 340 }
nuclear@9 341
nuclear@9 342 float4 pv0 = face->v[0].pos - pt;
nuclear@9 343 float4 pv1 = face->v[1].pos - pt;
nuclear@9 344 float4 pv2 = face->v[2].pos - pt;
nuclear@9 345
nuclear@12 346 // calculate the area of each sub-triangle
nuclear@12 347 float4 x12 = cross(pv1, pv2);
nuclear@12 348 float4 x20 = cross(pv2, pv0);
nuclear@12 349 float4 x01 = cross(pv0, pv1);
nuclear@12 350
nuclear@16 351 float a0 = fabs(dot(x12, norm)) * 0.5;
nuclear@16 352 float a1 = fabs(dot(x20, norm)) * 0.5;
nuclear@16 353 float a2 = fabs(dot(x01, norm)) * 0.5;
nuclear@9 354
nuclear@43 355 bc.x = native_divide(a0, area);
nuclear@43 356 bc.y = native_divide(a1, area);
nuclear@43 357 bc.z = native_divide(a2, area);
nuclear@9 358 return bc;
nuclear@9 359 }
nuclear@19 360
nuclear@19 361 float mean(float4 v)
nuclear@19 362 {
nuclear@19 363 return native_divide(v.x + v.y + v.z, 3.0);
nuclear@19 364 }
nuclear@43 365
nuclear@43 366
nuclear@43 367 const sampler_t kdsampler = CLK_NORMALIZED_COORDS_FALSE | CLK_ADDRESS_NONE | CLK_FILTER_NEAREST;
nuclear@43 368
nuclear@43 369 // read a KD-tree node from a texture scanline
nuclear@43 370 void read_kdnode(int idx, struct KDNode *node, read_only image2d_t kdimg)
nuclear@43 371 {
nuclear@45 372 int startx = KDIMG_NODE_WIDTH * (idx / KDIMG_MAX_HEIGHT);
nuclear@45 373
nuclear@43 374 int2 tc;
nuclear@45 375 tc.x = startx;
nuclear@45 376 tc.y = idx % KDIMG_MAX_HEIGHT;
nuclear@43 377
nuclear@43 378 node->aabb.min = read_imagef(kdimg, kdsampler, tc); tc.x++;
nuclear@43 379 node->aabb.max = read_imagef(kdimg, kdsampler, tc);
nuclear@43 380
nuclear@45 381 tc.x = startx + 2 + MAX_NODE_FACES / 4;
nuclear@43 382 float4 pix = read_imagef(kdimg, kdsampler, tc);
nuclear@43 383 node->num_faces = (int)pix.x;
nuclear@43 384 node->left = (int)pix.y;
nuclear@43 385 node->right = (int)pix.z;
nuclear@43 386
nuclear@45 387 tc.x = startx + 2;
nuclear@43 388 for(int i=0; i<node->num_faces; i+=4) {
nuclear@43 389 float4 pix = read_imagef(kdimg, kdsampler, tc); tc.x++;
nuclear@43 390 node->face_idx[i] = (int)pix.x;
nuclear@43 391 node->face_idx[i + 1] = (int)pix.y;
nuclear@43 392 node->face_idx[i + 2] = (int)pix.z;
nuclear@43 393 node->face_idx[i + 3] = (int)pix.w;
nuclear@43 394 }
nuclear@43 395 }