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Diffstat (limited to 'intern/cycles/kernel/kernel_mbvh.h')
| -rw-r--r-- | intern/cycles/kernel/kernel_mbvh.h | 394 |
1 files changed, 394 insertions, 0 deletions
diff --git a/intern/cycles/kernel/kernel_mbvh.h b/intern/cycles/kernel/kernel_mbvh.h new file mode 100644 index 00000000000..3995e782abd --- /dev/null +++ b/intern/cycles/kernel/kernel_mbvh.h @@ -0,0 +1,394 @@ +/* + * Copyright 2011, Blender Foundation. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software Foundation, + * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + */ + +CCL_NAMESPACE_BEGIN + +#define MBVH_OBJECT_SENTINEL 0x76543210 +#define MBVH_NODE_SIZE 8 +#define MBVH_STACK_SIZE 1024 +#define MBVH_RAY_STACK_SIZE 10000 + +typedef struct MBVHTask { + int node; + int index; + int num; + int object; +} MBVHTask; + +typedef struct MVBHRay { + float3 P; + float u; + float3 idir; + float v; + float t; + int index; + int object; + + float3 origP; + float3 origD; + float tmax; +} MBVHRay; + +__device float3 mbvh_inverse_direction(float3 dir) +{ + // Avoid divide by zero (ooeps = exp2f(-80.0f)) + float ooeps = 0.00000000000000000000000082718061255302767487140869206996285356581211090087890625f; + float3 idir; + + idir.x = 1.0f / (fabsf(dir.x) > ooeps ? dir.x : copysignf(ooeps, dir.x)); + idir.y = 1.0f / (fabsf(dir.y) > ooeps ? dir.y : copysignf(ooeps, dir.y)); + idir.z = 1.0f / (fabsf(dir.z) > ooeps ? dir.z : copysignf(ooeps, dir.z)); + + return idir; +} + +__device void mbvh_instance_push(KernelGlobals *kg, int object, MBVHRay *ray) +{ + Transform tfm = object_fetch_transform(kg, object, OBJECT_INVERSE_TRANSFORM); + + ray->P = transform(&tfm, ray->origP); + + float3 dir = ray->origD; + + if(ray->t != ray->tmax) dir *= ray->t; + + dir = transform_direction(&tfm, dir); + ray->idir = mbvh_inverse_direction(normalize(dir)); + + if(ray->t != ray->tmax) ray->t = len(dir); +} + +__device void mbvh_instance_pop(KernelGlobals *kg, int object, MBVHRay *ray) +{ + Transform tfm = object_fetch_transform(kg, object, OBJECT_TRANSFORM); + + if(ray->t != ray->tmax) + ray->t = len(transform_direction(&tfm, (1.0f/(ray->idir)) * (ray->t))); + + ray->P = ray->origP; + ray->idir = mbvh_inverse_direction(ray->origD); +} + +/* Sven Woop's algorithm */ +__device void mbvh_triangle_intersect(KernelGlobals *kg, MBVHRay *ray, int object, int triAddr) +{ + float3 P = ray->P; + float3 idir = ray->idir; + + /* compute and check intersection t-value */ + float4 v00 = kernel_tex_fetch(__tri_woop, triAddr*MBVH_NODE_SIZE+0); + float4 v11 = kernel_tex_fetch(__tri_woop, triAddr*MBVH_NODE_SIZE+1); + float3 dir = 1.0f/idir; + + float Oz = v00.w - P.x*v00.x - P.y*v00.y - P.z*v00.z; + float invDz = 1.0f/(dir.x*v00.x + dir.y*v00.y + dir.z*v00.z); + float t = Oz * invDz; + + if(t > 0.0f && t < ray->t) { + /* compute and check barycentric u */ + float Ox = v11.w + P.x*v11.x + P.y*v11.y + P.z*v11.z; + float Dx = dir.x*v11.x + dir.y*v11.y + dir.z*v11.z; + float u = Ox + t*Dx; + + if(u >= 0.0f) { + /* compute and check barycentric v */ + float4 v22 = kernel_tex_fetch(__tri_woop, triAddr*MBVH_NODE_SIZE+2); + float Oy = v22.w + P.x*v22.x + P.y*v22.y + P.z*v22.z; + float Dy = dir.x*v22.x + dir.y*v22.y + dir.z*v22.z; + float v = Oy + t*Dy; + + if(v >= 0.0f && u + v <= 1.0f) { + /* record intersection */ + ray->index = triAddr; + ray->object = object; + ray->u = u; + ray->v = v; + ray->t = t; + } + } + } +} + +__device void mbvh_node_intersect(KernelGlobals *kg, __m128 *traverseChild, + __m128 *tHit, float3 P, float3 idir, float t, int nodeAddr) +{ + /* X axis */ + const __m128 bminx = kernel_tex_fetch_m128(__bvh_nodes, nodeAddr*MBVH_NODE_SIZE+0); + const __m128 t0x = _mm_mul_ps(_mm_sub_ps(bminx, _mm_set_ps1(P.x)), _mm_set_ps1(idir.x)); + const __m128 bmaxx = kernel_tex_fetch_m128(__bvh_nodes, nodeAddr*MBVH_NODE_SIZE+1); + const __m128 t1x = _mm_mul_ps(_mm_sub_ps(bmaxx, _mm_set_ps1(P.x)), _mm_set_ps1(idir.x)); + + __m128 tmin = _mm_max_ps(_mm_min_ps(t0x, t1x), _mm_setzero_ps()); + __m128 tmax = _mm_min_ps(_mm_max_ps(t0x, t1x), _mm_set_ps1(t)); + + /* Y axis */ + const __m128 bminy = kernel_tex_fetch_m128(__bvh_nodes, nodeAddr*MBVH_NODE_SIZE+2); + const __m128 t0y = _mm_mul_ps(_mm_sub_ps(bminy, _mm_set_ps1(P.y)), _mm_set_ps1(idir.y)); + const __m128 bmaxy = kernel_tex_fetch_m128(__bvh_nodes, nodeAddr*MBVH_NODE_SIZE+3); + const __m128 t1y = _mm_mul_ps(_mm_sub_ps(bmaxy, _mm_set_ps1(P.y)), _mm_set_ps1(idir.y)); + + tmin = _mm_max_ps(_mm_min_ps(t0y, t1y), tmin); + tmax = _mm_min_ps(_mm_max_ps(t0y, t1y), tmax); + + /* Z axis */ + const __m128 bminz = kernel_tex_fetch_m128(__bvh_nodes, nodeAddr*MBVH_NODE_SIZE+4); + const __m128 t0z = _mm_mul_ps(_mm_sub_ps(bminz, _mm_set_ps1(P.z)), _mm_set_ps1(idir.z)); + const __m128 bmaxz = kernel_tex_fetch_m128(__bvh_nodes, nodeAddr*MBVH_NODE_SIZE+5); + const __m128 t1z = _mm_mul_ps(_mm_sub_ps(bmaxz, _mm_set_ps1(P.z)), _mm_set_ps1(idir.z)); + + tmin = _mm_max_ps(_mm_min_ps(t0z, t1z), tmin); + tmax = _mm_min_ps(_mm_max_ps(t0z, t1z), tmax); + + /* compare and get mask */ + *traverseChild = _mm_cmple_ps(tmin, tmax); + + /* get distance XXX probably wrong */ + *tHit = tmin; +} + +static void mbvh_sort_by_length(int id[4], float len[4]) +{ + for(int i = 1; i < 4; i++) { + int j = i - 1; + + while(j >= 0 && len[j] > len[j+1]) { + swap(len[j], len[j+1]); + swap(id[j], id[j+1]); + j--; + } + } +} + +__device void scene_intersect(KernelGlobals *kg, MBVHRay *rays, int numrays) +{ + /* traversal stacks */ + MBVHTask task_stack[MBVH_STACK_SIZE]; + int active_ray_stacks[4][MBVH_RAY_STACK_SIZE]; + int num_task, num_active[4] = {0, 0, 0, 0}; + __m128i one_mm = _mm_set1_epi32(1); + + /* push root node task on stack */ + task_stack[0].node = kernel_data.bvh.root; + task_stack[0].index = 0; + task_stack[0].num = numrays; + task_stack[0].object = ~0; + num_task = 1; + + /* push all rays in first SIMD lane */ + for(int i = 0; i < numrays; i++) + active_ray_stacks[0][i] = i; + num_active[0] = numrays; + + while(num_task >= 1) { + /* pop task */ + MBVHTask task = task_stack[--num_task]; + + if(task.node == MBVH_OBJECT_SENTINEL) { + /* instance pop */ + + /* pop rays from stack */ + num_active[task.index] -= task.num; + int ray_offset = num_active[task.index]; + + /* transform rays */ + for(int i = 0; i < task.num; i++) { + MBVHRay *ray = &rays[active_ray_stacks[task.index][ray_offset + i]]; + mbvh_instance_pop(kg, task.object, ray); + } + } + else if(task.node >= 0) { + /* inner node? */ + + /* pop rays from stack*/ + num_active[task.index] -= task.num; + int ray_offset = num_active[task.index]; + + /* initialze simd values */ + __m128i num_active_mm = _mm_load_si128((__m128i*)num_active); + __m128 len_mm = _mm_set_ps1(0.0f); + + for(int i = 0; i < task.num; i++) { + int rayid = active_ray_stacks[task.index][ray_offset + i]; + MVBHRay *ray = rays + rayid; + + /* intersect 4 QBVH node children */ + __m128 result; + __m128 thit; + + mbvh_node_intersect(kg, &result, &thit, ray->P, ray->idir, ray->t, task.node); + + /* update length for sorting */ + len_mm = _mm_add_ps(len_mm, _mm_and_ps(thit, result)); + + /* push rays on stack */ + for(int j = 0; j < 4; j++) + active_ray_stacks[j][num_active[j]] = rayid; + + /* update num active */ + __m128i resulti = _mm_and_si128(*((__m128i*)&result), one_mm); + num_active_mm = _mm_add_epi32(resulti, num_active_mm); + _mm_store_si128((__m128i*)num_active, num_active_mm); + } + + if(num_active[0] || num_active[1] || num_active[2] || num_active[3]) { + /* load child node addresses */ + float4 cnodes = kernel_tex_fetch(__bvh_nodes, task.node); + int child[4] = { + __float_as_int(cnodes.x), + __float_as_int(cnodes.y), + __float_as_int(cnodes.z), + __float_as_int(cnodes.w)}; + + /* sort nodes by average intersection distance */ + int ids[4] = {0, 1, 2, 3}; + float len[4]; + + _mm_store_ps(len, len_mm); + mbvh_sort_by_length(ids, len); + + /* push new tasks on stack */ + for(int j = 0; j < 4; j++) { + if(num_active[j]) { + int id = ids[j]; + + task_stack[num_task].node = child[id]; + task_stack[num_task].index = id; + task_stack[num_task].num = num_active[id]; + task_stack[num_task].object = task.object; + num_task++; + } + } + } + } + else { + /* fetch leaf node data */ + float4 leaf = kernel_tex_fetch(__bvh_nodes, (-task.node-1)*MBVH_NODE_SIZE+(MBVH_NODE_SIZE-2)); + int triAddr = __float_as_int(leaf.x); + int triAddr2 = __float_as_int(leaf.y); + + /* pop rays from stack*/ + num_active[task.index] -= task.num; + int ray_offset = num_active[task.index]; + + /* triangles */ + if(triAddr >= 0) { + int i, numq = (task.num >> 2) << 2; + + /* SIMD ray leaf intersection */ + for(i = 0; i < numq; i += 4) { + MBVHRay *ray4[4] = { + &rays[active_ray_stacks[task.index][ray_offset + i + 0]], + &rays[active_ray_stacks[task.index][ray_offset + i + 1]], + &rays[active_ray_stacks[task.index][ray_offset + i + 2]], + &rays[active_ray_stacks[task.index][ray_offset + i + 3]]}; + + /* load SoA */ + + while(triAddr < triAddr2) { + mbvh_triangle_intersect(ray4[0], task.object, task.node); + mbvh_triangle_intersect(ray4[1], task.object, task.node); + mbvh_triangle_intersect(ray4[2], task.object, task.node); + mbvh_triangle_intersect(ray4[3], task.object, task.node); + triAddr++; + + /* some shadow ray optim could be done by setting t=0 */ + } + + /* store AoS */ + } + + /* mono ray leaf intersection */ + for(; i < task.num; i++) { + MBVHRay *ray = &rays[active_ray_stacks[task.index][ray_offset + i]]; + + while(triAddr < triAddr2) { + mbvh_triangle_intersect(kg, ray, task.object, task.node); + triAddr++; + } + } + } + else { + /* instance push */ + int object = -triAddr-1; + int node = triAddr; + + /* push instance pop task */ + task_stack[num_task].node = MBVH_OBJECT_SENTINEL; + task_stack[num_task].index = task.index; + task_stack[num_task].num = task.num; + task_stack[num_task].object = object; + num_task++; + + num_active[task.index] += task.num; + + /* push node task */ + task_stack[num_task].node = node; + task_stack[num_task].index = task.index; + task_stack[num_task].num = task.num; + task_stack[num_task].object = object; + num_task++; + + for(int i = 0; i < task.num; i++) { + int rayid = active_ray_stacks[task.index][ray_offset + i]; + + /* push on stack for last task */ + active_ray_stacks[task.index][num_active[task.index]] = rayid; + num_active[task.index]++; + + /* transform ray */ + MBVHRay *ray = &rays[rayid]; + mbvh_instance_push(kg, object, ray); + } + } + } + } +} + +__device void mbvh_set_ray(MBVHRay *rays, int i, Ray *ray, float tmax) +{ + MBVHRay *mray = &rays[i]; + + /* ray parameters in registers */ + mray->P = ray->P; + mray->idir = mbvh_inverse_direction(ray->D); + mray->t = tmax; +} + +__device bool mbvh_get_intersection(MVBHRay *rays, int i, Intersection *isect, float tmax) +{ + MBVHRay *mray = &rays[i]; + + if(mray->t == tmax) + return false; + + isect->t = mray->t; + isect->u = mray->u; + isect->v = mray->v; + isect->index = mray->index; + isect->object = mray->object; + + return true; +} + +__device bool mbvh_get_shadow(MBVHRay *rays, int i, float tmax) +{ + return (rays[i].t == tmax); +} + +CCL_NAMESPACE_END + |