intern/cycles/kernel/geom/geom_bvh_volume.h

   1 /*
   2  * Adapted from code Copyright 2009-2010 NVIDIA Corporation,
   3  * and code copyright 2009-2012 Intel Corporation
   4  *
   5  * Modifications Copyright 2011-2014, Blender Foundation.
   6  *
   7  * Licensed under the Apache License, Version 2.0 (the "License");
   8  * you may not use this file except in compliance with the License.
   9  * You may obtain a copy of the License at
  10  *
  11  * http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  * Unless required by applicable law or agreed to in writing, software
  14  * distributed under the License is distributed on an "AS IS" BASIS,
  15  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  * See the License for the specific language governing permissions and
  17  * limitations under the License.
  18  */
  19
  20 #ifdef __QBVH__
  21 #include "geom_qbvh_volume.h"
  22 #endif
  23
  24 /* This is a template BVH traversal function for volumes, where
  25  * various features can be enabled/disabled. This way we can compile optimized
  26  * versions for each case without new features slowing things down.
  27  *
  28  * BVH_INSTANCING: object instancing
  29  * BVH_HAIR: hair curve rendering
  30  * BVH_MOTION: motion blur rendering
  31  *
  32  */
  33
  34 ccl_device bool BVH_FUNCTION_FULL_NAME(BVH)(KernelGlobals *kg,
  35                                             const Ray *ray,
  36                                             Intersection *isect)
  37 {
  38         /* todo:
  39          * - test if pushing distance on the stack helps (for non shadow rays)
  40          * - separate version for shadow rays
  41          * - likely and unlikely for if() statements
  42          * - test restrict attribute for pointers
  43          */
  44
  45         /* traversal stack in CUDA thread-local memory */
  46         int traversalStack[BVH_STACK_SIZE];
  47         traversalStack[0] = ENTRYPOINT_SENTINEL;
  48
  49         /* traversal variables in registers */
  50         int stackPtr = 0;
  51         int nodeAddr = kernel_data.bvh.root;
  52
  53         /* ray parameters in registers */
  54         float3 P = ray->P;
  55         float3 dir = bvh_clamp_direction(ray->D);
  56         float3 idir = bvh_inverse_direction(dir);
  57         int object = OBJECT_NONE;
  58
  59         const uint visibility = PATH_RAY_ALL_VISIBILITY;
  60
  61 #if BVH_FEATURE(BVH_MOTION)
  62         Transform ob_itfm;
  63 #endif
  64
  65         isect->t = ray->t;
  66         isect->u = 0.0f;
  67         isect->v = 0.0f;
  68         isect->prim = PRIM_NONE;
  69         isect->object = OBJECT_NONE;
  70
  71 #if defined(__KERNEL_SSE2__)
  72         const shuffle_swap_t shuf_identity = shuffle_swap_identity();
  73         const shuffle_swap_t shuf_swap = shuffle_swap_swap();
  74
  75         const ssef pn = cast(ssei(0, 0, 0x80000000, 0x80000000));
  76         ssef Psplat[3], idirsplat[3];
  77         shuffle_swap_t shufflexyz[3];
  78
  79         Psplat[0] = ssef(P.x);
  80         Psplat[1] = ssef(P.y);
  81         Psplat[2] = ssef(P.z);
  82
  83         ssef tsplat(0.0f, 0.0f, -isect->t, -isect->t);
  84
  85         gen_idirsplat_swap(pn, shuf_identity, shuf_swap, idir, idirsplat, shufflexyz);
  86 #endif
  87
  88         IsectPrecalc isect_precalc;
  89         triangle_intersect_precalc(dir, &isect_precalc);
  90
  91         /* traversal loop */
  92         do {
  93                 do {
  94                         /* traverse internal nodes */
  95                         while(nodeAddr >= 0 && nodeAddr != ENTRYPOINT_SENTINEL) {
  96                                 bool traverseChild0, traverseChild1;
  97                                 int nodeAddrChild1;
  98
  99 #if !defined(__KERNEL_SSE2__)
 100                                 /* Intersect two child bounding boxes, non-SSE version */
 101                                 float t = isect->t;
 102
 103                                 /* fetch node data */
 104                                 float4 node0 = kernel_tex_fetch(__bvh_nodes, nodeAddr*BVH_NODE_SIZE+0);
 105                                 float4 node1 = kernel_tex_fetch(__bvh_nodes, nodeAddr*BVH_NODE_SIZE+1);
 106                                 float4 node2 = kernel_tex_fetch(__bvh_nodes, nodeAddr*BVH_NODE_SIZE+2);
 107                                 float4 cnodes = kernel_tex_fetch(__bvh_nodes, nodeAddr*BVH_NODE_SIZE+3);
 108
 109                                 /* intersect ray against child nodes */
 110                                 NO_EXTENDED_PRECISION float c0lox = (node0.x - P.x) * idir.x;
 111                                 NO_EXTENDED_PRECISION float c0hix = (node0.z - P.x) * idir.x;
 112                                 NO_EXTENDED_PRECISION float c0loy = (node1.x - P.y) * idir.y;
 113                                 NO_EXTENDED_PRECISION float c0hiy = (node1.z - P.y) * idir.y;
 114                                 NO_EXTENDED_PRECISION float c0loz = (node2.x - P.z) * idir.z;
 115                                 NO_EXTENDED_PRECISION float c0hiz = (node2.z - P.z) * idir.z;
 116                                 NO_EXTENDED_PRECISION float c0min = max4(min(c0lox, c0hix), min(c0loy, c0hiy), min(c0loz, c0hiz), 0.0f);
 117                                 NO_EXTENDED_PRECISION float c0max = min4(max(c0lox, c0hix), max(c0loy, c0hiy), max(c0loz, c0hiz), t);
 118
 119                                 NO_EXTENDED_PRECISION float c1lox = (node0.y - P.x) * idir.x;
 120                                 NO_EXTENDED_PRECISION float c1hix = (node0.w - P.x) * idir.x;
 121                                 NO_EXTENDED_PRECISION float c1loy = (node1.y - P.y) * idir.y;
 122                                 NO_EXTENDED_PRECISION float c1hiy = (node1.w - P.y) * idir.y;
 123                                 NO_EXTENDED_PRECISION float c1loz = (node2.y - P.z) * idir.z;
 124                                 NO_EXTENDED_PRECISION float c1hiz = (node2.w - P.z) * idir.z;
 125                                 NO_EXTENDED_PRECISION float c1min = max4(min(c1lox, c1hix), min(c1loy, c1hiy), min(c1loz, c1hiz), 0.0f);
 126                                 NO_EXTENDED_PRECISION float c1max = min4(max(c1lox, c1hix), max(c1loy, c1hiy), max(c1loz, c1hiz), t);
 127
 128                                 /* decide which nodes to traverse next */
 129                                 traverseChild0 = (c0max >= c0min);
 130                                 traverseChild1 = (c1max >= c1min);
 131
 132 #else // __KERNEL_SSE2__
 133                                 /* Intersect two child bounding boxes, SSE3 version adapted from Embree */
 134
 135                                 /* fetch node data */
 136                                 const ssef *bvh_nodes = (ssef*)kg->__bvh_nodes.data + nodeAddr*BVH_NODE_SIZE;
 137                                 const float4 cnodes = ((float4*)bvh_nodes)[3];
 138
 139                                 /* intersect ray against child nodes */
 140                                 const ssef tminmaxx = (shuffle_swap(bvh_nodes[0], shufflexyz[0]) - Psplat[0]) * idirsplat[0];
 141                                 const ssef tminmaxy = (shuffle_swap(bvh_nodes[1], shufflexyz[1]) - Psplat[1]) * idirsplat[1];
 142                                 const ssef tminmaxz = (shuffle_swap(bvh_nodes[2], shufflexyz[2]) - Psplat[2]) * idirsplat[2];
 143
 144                                 /* calculate { c0min, c1min, -c0max, -c1max} */
 145                                 ssef minmax = max(max(tminmaxx, tminmaxy), max(tminmaxz, tsplat));
 146                                 const ssef tminmax = minmax ^ pn;
 147
 148                                 const sseb lrhit = tminmax <= shuffle<2, 3, 0, 1>(tminmax);
 149
 150                                 /* decide which nodes to traverse next */
 151                                 traverseChild0 = (movemask(lrhit) & 1);
 152                                 traverseChild1 = (movemask(lrhit) & 2);
 153 #endif // __KERNEL_SSE2__
 154
 155                                 nodeAddr = __float_as_int(cnodes.x);
 156                                 nodeAddrChild1 = __float_as_int(cnodes.y);
 157
 158                                 if(traverseChild0 && traverseChild1) {
 159                                         /* both children were intersected, push the farther one */
 160 #if !defined(__KERNEL_SSE2__)
 161                                         bool closestChild1 = (c1min < c0min);
 162 #else
 163                                         bool closestChild1 = tminmax[1] < tminmax[0];
 164 #endif
 165
 166                                         if(closestChild1) {
 167                                                 int tmp = nodeAddr;
 168                                                 nodeAddr = nodeAddrChild1;
 169                                                 nodeAddrChild1 = tmp;
 170                                         }
 171
 172                                         ++stackPtr;
 173                                         kernel_assert(stackPtr < BVH_STACK_SIZE);
 174                                         traversalStack[stackPtr] = nodeAddrChild1;
 175                                 }
 176                                 else {
 177                                         /* one child was intersected */
 178                                         if(traverseChild1) {
 179                                                 nodeAddr = nodeAddrChild1;
 180                                         }
 181                                         else if(!traverseChild0) {
 182                                                 /* neither child was intersected */
 183                                                 nodeAddr = traversalStack[stackPtr];
 184                                                 --stackPtr;
 185                                         }
 186                                 }
 187                         }
 188
 189                         /* if node is leaf, fetch triangle list */
 190                         if(nodeAddr < 0) {
 191                                 float4 leaf = kernel_tex_fetch(__bvh_leaf_nodes, (-nodeAddr-1)*BVH_NODE_LEAF_SIZE);
 192                                 int primAddr = __float_as_int(leaf.x);
 193
 194 #if BVH_FEATURE(BVH_INSTANCING)
 195                                 if(primAddr >= 0) {
 196 #endif
 197                                         const int primAddr2 = __float_as_int(leaf.y);
 198                                         const uint type = __float_as_int(leaf.w);
 199
 200                                         /* pop */
 201                                         nodeAddr = traversalStack[stackPtr];
 202                                         --stackPtr;
 203
 204                                         /* primitive intersection */
 205                                         switch(type & PRIMITIVE_ALL) {
 206                                                 case PRIMITIVE_TRIANGLE: {
 207                                                         /* intersect ray against primitive */
 208                                                         for(; primAddr < primAddr2; primAddr++) {
 209                                                                 kernel_assert(kernel_tex_fetch(__prim_type, primAddr) == type);
 210                                                                 /* only primitives from volume object */
 211                                                                 uint tri_object = (object == OBJECT_NONE)? kernel_tex_fetch(__prim_object, primAddr): object;
 212                                                                 int object_flag = kernel_tex_fetch(__object_flag, tri_object);
 213                                                                 if((object_flag & SD_OBJECT_HAS_VOLUME) == 0) {
 214                                                                         continue;
 215                                                                 }
 216                                                                 triangle_intersect(kg, &isect_precalc, isect, P, visibility, object, primAddr);
 217                                                         }
 218                                                         break;
 219                                                 }
 220 #if BVH_FEATURE(BVH_MOTION)
 221                                                 case PRIMITIVE_MOTION_TRIANGLE: {
 222                                                         /* intersect ray against primitive */
 223                                                         for(; primAddr < primAddr2; primAddr++) {
 224                                                                 kernel_assert(kernel_tex_fetch(__prim_type, primAddr) == type);
 225                                                                 /* only primitives from volume object */
 226                                                                 uint tri_object = (object == OBJECT_NONE)? kernel_tex_fetch(__prim_object, primAddr): object;
 227                                                                 int object_flag = kernel_tex_fetch(__object_flag, tri_object);
 228                                                                 if((object_flag & SD_OBJECT_HAS_VOLUME) == 0) {
 229                                                                         continue;
 230                                                                 }
 231                                                                 motion_triangle_intersect(kg, isect, P, dir, ray->time, visibility, object, primAddr);
 232                                                         }
 233                                                         break;
 234                                                 }
 235 #endif
 236 #if BVH_FEATURE(BVH_HAIR)
 237                                                 case PRIMITIVE_CURVE:
 238                                                 case PRIMITIVE_MOTION_CURVE: {
 239                                                         /* intersect ray against primitive */
 240                                                         for(; primAddr < primAddr2; primAddr++) {
 241                                                                 kernel_assert(kernel_tex_fetch(__prim_type, primAddr) == type);
 242                                                                 /* only primitives from volume object */
 243                                                                 uint tri_object = (object == OBJECT_NONE)? kernel_tex_fetch(__prim_object, primAddr): object;
 244                                                                 int object_flag = kernel_tex_fetch(__object_flag, tri_object);
 245                                                                 if((object_flag & SD_OBJECT_HAS_VOLUME) == 0) {
 246                                                                         continue;
 247                                                                 }
 248                                                                 if(kernel_data.curve.curveflags & CURVE_KN_INTERPOLATE)
 249                                                                         bvh_cardinal_curve_intersect(kg, isect, P, dir, visibility, object, primAddr, ray->time, type, NULL, 0, 0);
 250                                                                 else
 251                                                                         bvh_curve_intersect(kg, isect, P, dir, visibility, object, primAddr, ray->time, type, NULL, 0, 0);
 252                                                         }
 253                                                         break;
 254                                                 }
 255 #endif
 256                                                 default: {
 257                                                         break;
 258                                                 }
 259                                         }
 260                                 }
 261 #if BVH_FEATURE(BVH_INSTANCING)
 262                                 else {
 263                                         /* instance push */
 264                                         object = kernel_tex_fetch(__prim_object, -primAddr-1);
 265                                         int object_flag = kernel_tex_fetch(__object_flag, object);
 266
 267                                         if(object_flag & SD_OBJECT_HAS_VOLUME) {
 268
 269 #  if BVH_FEATURE(BVH_MOTION)
 270                                                 bvh_instance_motion_push(kg, object, ray, &P, &dir, &idir, &isect->t, &ob_itfm);
 271 #  else
 272                                                 bvh_instance_push(kg, object, ray, &P, &dir, &idir, &isect->t);
 273 #  endif
 274
 275                                                 triangle_intersect_precalc(dir, &isect_precalc);
 276
 277 #  if defined(__KERNEL_SSE2__)
 278                                                 Psplat[0] = ssef(P.x);
 279                                                 Psplat[1] = ssef(P.y);
 280                                                 Psplat[2] = ssef(P.z);
 281
 282                                                 tsplat = ssef(0.0f, 0.0f, -isect->t, -isect->t);
 283
 284                                                 gen_idirsplat_swap(pn, shuf_identity, shuf_swap, idir, idirsplat, shufflexyz);
 285 #  endif
 286
 287                                                 ++stackPtr;
 288                                                 kernel_assert(stackPtr < BVH_STACK_SIZE);
 289                                                 traversalStack[stackPtr] = ENTRYPOINT_SENTINEL;
 290
 291                                                 nodeAddr = kernel_tex_fetch(__object_node, object);
 292                                         }
 293                                         else {
 294                                                 /* pop */
 295                                                 object = OBJECT_NONE;
 296                                                 nodeAddr = traversalStack[stackPtr];
 297                                                 --stackPtr;
 298                                         }
 299                                 }
 300                         }
 301 #endif  /* FEATURE(BVH_INSTANCING) */
 302                 } while(nodeAddr != ENTRYPOINT_SENTINEL);
 303
 304 #if BVH_FEATURE(BVH_INSTANCING)
 305                 if(stackPtr >= 0) {
 306                         kernel_assert(object != OBJECT_NONE);
 307
 308                         /* instance pop */
 309 #  if BVH_FEATURE(BVH_MOTION)
 310                         bvh_instance_motion_pop(kg, object, ray, &P, &dir, &idir, &isect->t, &ob_itfm);
 311 #  else
 312                         bvh_instance_pop(kg, object, ray, &P, &dir, &idir, &isect->t);
 313 #  endif
 314
 315                         triangle_intersect_precalc(dir, &isect_precalc);
 316
 317 #  if defined(__KERNEL_SSE2__)
 318                         Psplat[0] = ssef(P.x);
 319                         Psplat[1] = ssef(P.y);
 320                         Psplat[2] = ssef(P.z);
 321
 322                         tsplat = ssef(0.0f, 0.0f, -isect->t, -isect->t);
 323
 324                         gen_idirsplat_swap(pn, shuf_identity, shuf_swap, idir, idirsplat, shufflexyz);
 325 #  endif
 326
 327                         object = OBJECT_NONE;
 328                         nodeAddr = traversalStack[stackPtr];
 329                         --stackPtr;
 330                 }
 331 #endif  /* FEATURE(BVH_MOTION) */
 332         } while(nodeAddr != ENTRYPOINT_SENTINEL);
 333
 334         return (isect->prim != PRIM_NONE);
 335 }
 336
 337 ccl_device_inline bool BVH_FUNCTION_NAME(KernelGlobals *kg,
 338                                          const Ray *ray,
 339                                          Intersection *isect)
 340 {
 341 #ifdef __QBVH__
 342         if(kernel_data.bvh.use_qbvh) {
 343                 return BVH_FUNCTION_FULL_NAME(QBVH)(kg,
 344                                                     ray,
 345                                                     isect);
 346         }
 347         else
 348 #endif
 349         {
 350                 kernel_assert(kernel_data.bvh.use_qbvh == false);
 351                 return BVH_FUNCTION_FULL_NAME(BVH)(kg,
 352                                                    ray,
 353                                                    isect);
 354         }
 355 }
 356
 357 #undef BVH_FUNCTION_NAME
 358 #undef BVH_FUNCTION_FEATURES