Files
blender/intern/cycles/kernel/bvh/obvh_traversal.h
2019-05-01 21:41:07 +10:00

558 lines
20 KiB
C

/*
* Copyright 2011-2013 Blender Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* This is a template BVH traversal function, where various features can be
* enabled/disabled. This way we can compile optimized versions for each case
* without new features slowing things down.
*
* BVH_INSTANCING: object instancing
* BVH_HAIR: hair curve rendering
* BVH_MOTION: motion blur rendering
*/
#if BVH_FEATURE(BVH_HAIR)
# define NODE_INTERSECT obvh_node_intersect
#else
# define NODE_INTERSECT obvh_aligned_node_intersect
#endif
ccl_device bool BVH_FUNCTION_FULL_NAME(OBVH)(KernelGlobals *kg,
const Ray *ray,
Intersection *isect,
const uint visibility)
{
/* Traversal stack in CUDA thread-local memory. */
OBVHStackItem traversal_stack[BVH_OSTACK_SIZE];
traversal_stack[0].addr = ENTRYPOINT_SENTINEL;
traversal_stack[0].dist = -FLT_MAX;
/* Traversal variables in registers. */
int stack_ptr = 0;
int node_addr = kernel_data.bvh.root;
float node_dist = -FLT_MAX;
/* Ray parameters in registers. */
float3 P = ray->P;
float3 dir = bvh_clamp_direction(ray->D);
float3 idir = bvh_inverse_direction(dir);
int object = OBJECT_NONE;
#if BVH_FEATURE(BVH_MOTION)
Transform ob_itfm;
#endif
isect->t = ray->t;
isect->u = 0.0f;
isect->v = 0.0f;
isect->prim = PRIM_NONE;
isect->object = OBJECT_NONE;
BVH_DEBUG_INIT();
avxf tnear(0.0f), tfar(ray->t);
#if BVH_FEATURE(BVH_HAIR)
avx3f dir4(avxf(dir.x), avxf(dir.y), avxf(dir.z));
#endif
avx3f idir4(avxf(idir.x), avxf(idir.y), avxf(idir.z));
#ifdef __KERNEL_AVX2__
float3 P_idir = P * idir;
avx3f P_idir4 = avx3f(P_idir.x, P_idir.y, P_idir.z);
#endif
#if BVH_FEATURE(BVH_HAIR) || !defined(__KERNEL_AVX2__)
avx3f org4 = avx3f(avxf(P.x), avxf(P.y), avxf(P.z));
#endif
/* Offsets to select the side that becomes the lower or upper bound. */
int near_x, near_y, near_z;
int far_x, far_y, far_z;
obvh_near_far_idx_calc(idir, &near_x, &near_y, &near_z, &far_x, &far_y, &far_z);
/* Traversal loop. */
do {
do {
/* Traverse internal nodes. */
while (node_addr >= 0 && node_addr != ENTRYPOINT_SENTINEL) {
float4 inodes = kernel_tex_fetch(__bvh_nodes, node_addr + 0);
(void)inodes;
if (UNLIKELY(node_dist > isect->t)
#if BVH_FEATURE(BVH_MOTION)
|| UNLIKELY(ray->time < inodes.y) || UNLIKELY(ray->time > inodes.z)
#endif
#ifdef __VISIBILITY_FLAG__
|| (__float_as_uint(inodes.x) & visibility) == 0
#endif
) {
/* Pop. */
node_addr = traversal_stack[stack_ptr].addr;
node_dist = traversal_stack[stack_ptr].dist;
--stack_ptr;
continue;
}
int child_mask;
avxf dist;
BVH_DEBUG_NEXT_NODE();
{
child_mask = NODE_INTERSECT(kg,
tnear,
tfar,
#ifdef __KERNEL_AVX2__
P_idir4,
#endif
#if BVH_FEATURE(BVH_HAIR) || !defined(__KERNEL_AVX2__)
org4,
#endif
#if BVH_FEATURE(BVH_HAIR)
dir4,
#endif
idir4,
near_x,
near_y,
near_z,
far_x,
far_y,
far_z,
node_addr,
&dist);
}
if (child_mask != 0) {
avxf cnodes;
/* TODO(sergey): Investigate whether moving cnodes upwards
* gives a speedup (will be different cache pattern but will
* avoid extra check here).
*/
#if BVH_FEATURE(BVH_HAIR)
if (__float_as_uint(inodes.x) & PATH_RAY_NODE_UNALIGNED) {
cnodes = kernel_tex_fetch_avxf(__bvh_nodes, node_addr + 26);
}
else
#endif
{
cnodes = kernel_tex_fetch_avxf(__bvh_nodes, node_addr + 14);
}
/* One child is hit, continue with that child. */
int r = __bscf(child_mask);
float d0 = ((float *)&dist)[r];
if (child_mask == 0) {
node_addr = __float_as_int(cnodes[r]);
node_dist = d0;
continue;
}
/* Two children are hit, push far child, and continue with
* closer child.
*/
int c0 = __float_as_int(cnodes[r]);
r = __bscf(child_mask);
int c1 = __float_as_int(cnodes[r]);
float d1 = ((float *)&dist)[r];
if (child_mask == 0) {
if (d1 < d0) {
node_addr = c1;
node_dist = d1;
++stack_ptr;
kernel_assert(stack_ptr < BVH_OSTACK_SIZE);
traversal_stack[stack_ptr].addr = c0;
traversal_stack[stack_ptr].dist = d0;
continue;
}
else {
node_addr = c0;
node_dist = d0;
++stack_ptr;
kernel_assert(stack_ptr < BVH_OSTACK_SIZE);
traversal_stack[stack_ptr].addr = c1;
traversal_stack[stack_ptr].dist = d1;
continue;
}
}
/* Here starts the slow path for 3 or 4 hit children. We push
* all nodes onto the stack to sort them there.
*/
++stack_ptr;
kernel_assert(stack_ptr < BVH_OSTACK_SIZE);
traversal_stack[stack_ptr].addr = c1;
traversal_stack[stack_ptr].dist = d1;
++stack_ptr;
kernel_assert(stack_ptr < BVH_OSTACK_SIZE);
traversal_stack[stack_ptr].addr = c0;
traversal_stack[stack_ptr].dist = d0;
/* Three children are hit, push all onto stack and sort 3
* stack items, continue with closest child.
*/
r = __bscf(child_mask);
int c2 = __float_as_int(cnodes[r]);
float d2 = ((float *)&dist)[r];
if (child_mask == 0) {
++stack_ptr;
kernel_assert(stack_ptr < BVH_OSTACK_SIZE);
traversal_stack[stack_ptr].addr = c2;
traversal_stack[stack_ptr].dist = d2;
obvh_stack_sort(&traversal_stack[stack_ptr],
&traversal_stack[stack_ptr - 1],
&traversal_stack[stack_ptr - 2]);
node_addr = traversal_stack[stack_ptr].addr;
node_dist = traversal_stack[stack_ptr].dist;
--stack_ptr;
continue;
}
/* Four children are hit, push all onto stack and sort 4
* stack items, continue with closest child.
*/
r = __bscf(child_mask);
int c3 = __float_as_int(cnodes[r]);
float d3 = ((float *)&dist)[r];
if (child_mask == 0) {
++stack_ptr;
kernel_assert(stack_ptr < BVH_OSTACK_SIZE);
traversal_stack[stack_ptr].addr = c3;
traversal_stack[stack_ptr].dist = d3;
++stack_ptr;
kernel_assert(stack_ptr < BVH_OSTACK_SIZE);
traversal_stack[stack_ptr].addr = c2;
traversal_stack[stack_ptr].dist = d2;
obvh_stack_sort(&traversal_stack[stack_ptr],
&traversal_stack[stack_ptr - 1],
&traversal_stack[stack_ptr - 2],
&traversal_stack[stack_ptr - 3]);
node_addr = traversal_stack[stack_ptr].addr;
node_dist = traversal_stack[stack_ptr].dist;
--stack_ptr;
continue;
}
++stack_ptr;
kernel_assert(stack_ptr < BVH_OSTACK_SIZE);
traversal_stack[stack_ptr].addr = c3;
traversal_stack[stack_ptr].dist = d3;
++stack_ptr;
kernel_assert(stack_ptr < BVH_OSTACK_SIZE);
traversal_stack[stack_ptr].addr = c2;
traversal_stack[stack_ptr].dist = d2;
/* Five children are hit, push all onto stack and sort 5
* stack items, continue with closest child.
*/
r = __bscf(child_mask);
int c4 = __float_as_int(cnodes[r]);
float d4 = ((float *)&dist)[r];
if (child_mask == 0) {
++stack_ptr;
kernel_assert(stack_ptr < BVH_OSTACK_SIZE);
traversal_stack[stack_ptr].addr = c4;
traversal_stack[stack_ptr].dist = d4;
obvh_stack_sort(&traversal_stack[stack_ptr],
&traversal_stack[stack_ptr - 1],
&traversal_stack[stack_ptr - 2],
&traversal_stack[stack_ptr - 3],
&traversal_stack[stack_ptr - 4]);
node_addr = traversal_stack[stack_ptr].addr;
node_dist = traversal_stack[stack_ptr].dist;
--stack_ptr;
continue;
}
/* Six children are hit, push all onto stack and sort 6
* stack items, continue with closest child.
*/
r = __bscf(child_mask);
int c5 = __float_as_int(cnodes[r]);
float d5 = ((float *)&dist)[r];
if (child_mask == 0) {
++stack_ptr;
kernel_assert(stack_ptr < BVH_OSTACK_SIZE);
traversal_stack[stack_ptr].addr = c5;
traversal_stack[stack_ptr].dist = d5;
++stack_ptr;
kernel_assert(stack_ptr < BVH_OSTACK_SIZE);
traversal_stack[stack_ptr].addr = c4;
traversal_stack[stack_ptr].dist = d4;
obvh_stack_sort(&traversal_stack[stack_ptr],
&traversal_stack[stack_ptr - 1],
&traversal_stack[stack_ptr - 2],
&traversal_stack[stack_ptr - 3],
&traversal_stack[stack_ptr - 4],
&traversal_stack[stack_ptr - 5]);
node_addr = traversal_stack[stack_ptr].addr;
node_dist = traversal_stack[stack_ptr].dist;
--stack_ptr;
continue;
}
++stack_ptr;
kernel_assert(stack_ptr < BVH_OSTACK_SIZE);
traversal_stack[stack_ptr].addr = c5;
traversal_stack[stack_ptr].dist = d5;
++stack_ptr;
kernel_assert(stack_ptr < BVH_OSTACK_SIZE);
traversal_stack[stack_ptr].addr = c4;
traversal_stack[stack_ptr].dist = d4;
/* Seven children are hit, push all onto stack and sort 7
* stack items, continue with closest child.
*/
r = __bscf(child_mask);
int c6 = __float_as_int(cnodes[r]);
float d6 = ((float *)&dist)[r];
if (child_mask == 0) {
++stack_ptr;
kernel_assert(stack_ptr < BVH_OSTACK_SIZE);
traversal_stack[stack_ptr].addr = c6;
traversal_stack[stack_ptr].dist = d6;
obvh_stack_sort(&traversal_stack[stack_ptr],
&traversal_stack[stack_ptr - 1],
&traversal_stack[stack_ptr - 2],
&traversal_stack[stack_ptr - 3],
&traversal_stack[stack_ptr - 4],
&traversal_stack[stack_ptr - 5],
&traversal_stack[stack_ptr - 6]);
node_addr = traversal_stack[stack_ptr].addr;
node_dist = traversal_stack[stack_ptr].dist;
--stack_ptr;
continue;
}
/* Eight children are hit, push all onto stack and sort 8
* stack items, continue with closest child.
*/
r = __bscf(child_mask);
int c7 = __float_as_int(cnodes[r]);
float d7 = ((float *)&dist)[r];
++stack_ptr;
kernel_assert(stack_ptr < BVH_OSTACK_SIZE);
traversal_stack[stack_ptr].addr = c7;
traversal_stack[stack_ptr].dist = d7;
++stack_ptr;
kernel_assert(stack_ptr < BVH_OSTACK_SIZE);
traversal_stack[stack_ptr].addr = c6;
traversal_stack[stack_ptr].dist = d6;
obvh_stack_sort(&traversal_stack[stack_ptr],
&traversal_stack[stack_ptr - 1],
&traversal_stack[stack_ptr - 2],
&traversal_stack[stack_ptr - 3],
&traversal_stack[stack_ptr - 4],
&traversal_stack[stack_ptr - 5],
&traversal_stack[stack_ptr - 6],
&traversal_stack[stack_ptr - 7]);
node_addr = traversal_stack[stack_ptr].addr;
node_dist = traversal_stack[stack_ptr].dist;
--stack_ptr;
continue;
}
node_addr = traversal_stack[stack_ptr].addr;
node_dist = traversal_stack[stack_ptr].dist;
--stack_ptr;
}
/* If node is leaf, fetch triangle list. */
if (node_addr < 0) {
float4 leaf = kernel_tex_fetch(__bvh_leaf_nodes, (-node_addr - 1));
#ifdef __VISIBILITY_FLAG__
if (UNLIKELY((node_dist > isect->t) || ((__float_as_uint(leaf.z) & visibility) == 0)))
#else
if (UNLIKELY((node_dist > isect->t)))
#endif
{
/* Pop. */
node_addr = traversal_stack[stack_ptr].addr;
node_dist = traversal_stack[stack_ptr].dist;
--stack_ptr;
continue;
}
int prim_addr = __float_as_int(leaf.x);
#if BVH_FEATURE(BVH_INSTANCING)
if (prim_addr >= 0) {
#endif
int prim_addr2 = __float_as_int(leaf.y);
const uint type = __float_as_int(leaf.w);
/* Pop. */
node_addr = traversal_stack[stack_ptr].addr;
node_dist = traversal_stack[stack_ptr].dist;
--stack_ptr;
/* Primitive intersection. */
switch (type & PRIMITIVE_ALL) {
case PRIMITIVE_TRIANGLE: {
int prim_count = prim_addr2 - prim_addr;
if (prim_count < 3) {
for (; prim_addr < prim_addr2; prim_addr++) {
BVH_DEBUG_NEXT_INTERSECTION();
kernel_assert(kernel_tex_fetch(__prim_type, prim_addr) == type);
if (triangle_intersect(kg, isect, P, dir, visibility, object, prim_addr)) {
tfar = avxf(isect->t);
/* Shadow ray early termination. */
if (visibility == PATH_RAY_SHADOW_OPAQUE) {
return true;
}
}
} // for
}
else {
kernel_assert(kernel_tex_fetch(__prim_type, prim_addr) == type);
if (triangle_intersect8(kg,
&isect,
P,
dir,
visibility,
object,
prim_addr,
prim_count,
0,
0,
NULL,
0.0f)) {
tfar = avxf(isect->t);
if (visibility == PATH_RAY_SHADOW_OPAQUE) {
return true;
}
}
} // prim count
break;
}
#if BVH_FEATURE(BVH_MOTION)
case PRIMITIVE_MOTION_TRIANGLE: {
for (; prim_addr < prim_addr2; prim_addr++) {
BVH_DEBUG_NEXT_INTERSECTION();
kernel_assert(kernel_tex_fetch(__prim_type, prim_addr) == type);
if (motion_triangle_intersect(
kg, isect, P, dir, ray->time, visibility, object, prim_addr)) {
tfar = avxf(isect->t);
/* Shadow ray early termination. */
if (visibility == PATH_RAY_SHADOW_OPAQUE) {
return true;
}
}
}
break;
}
#endif /* BVH_FEATURE(BVH_MOTION) */
#if BVH_FEATURE(BVH_HAIR)
case PRIMITIVE_CURVE:
case PRIMITIVE_MOTION_CURVE: {
for (; prim_addr < prim_addr2; prim_addr++) {
BVH_DEBUG_NEXT_INTERSECTION();
const uint curve_type = kernel_tex_fetch(__prim_type, prim_addr);
kernel_assert((curve_type & PRIMITIVE_ALL) == (type & PRIMITIVE_ALL));
bool hit;
if (kernel_data.curve.curveflags & CURVE_KN_INTERPOLATE) {
hit = cardinal_curve_intersect(
kg, isect, P, dir, visibility, object, prim_addr, ray->time, curve_type);
}
else {
hit = curve_intersect(
kg, isect, P, dir, visibility, object, prim_addr, ray->time, curve_type);
}
if (hit) {
tfar = avxf(isect->t);
/* Shadow ray early termination. */
if (visibility == PATH_RAY_SHADOW_OPAQUE) {
return true;
}
}
}
break;
}
#endif /* BVH_FEATURE(BVH_HAIR) */
}
}
#if BVH_FEATURE(BVH_INSTANCING)
else {
/* Instance push. */
object = kernel_tex_fetch(__prim_object, -prim_addr - 1);
# if BVH_FEATURE(BVH_MOTION)
qbvh_instance_motion_push(
kg, object, ray, &P, &dir, &idir, &isect->t, &node_dist, &ob_itfm);
# else
qbvh_instance_push(kg, object, ray, &P, &dir, &idir, &isect->t, &node_dist);
# endif
obvh_near_far_idx_calc(idir, &near_x, &near_y, &near_z, &far_x, &far_y, &far_z);
tfar = avxf(isect->t);
# if BVH_FEATURE(BVH_HAIR)
dir4 = avx3f(avxf(dir.x), avxf(dir.y), avxf(dir.z));
# endif
idir4 = avx3f(avxf(idir.x), avxf(idir.y), avxf(idir.z));
# ifdef __KERNEL_AVX2__
P_idir = P * idir;
P_idir4 = avx3f(P_idir.x, P_idir.y, P_idir.z);
# endif
# if BVH_FEATURE(BVH_HAIR) || !defined(__KERNEL_AVX2__)
org4 = avx3f(avxf(P.x), avxf(P.y), avxf(P.z));
# endif
++stack_ptr;
kernel_assert(stack_ptr < BVH_OSTACK_SIZE);
traversal_stack[stack_ptr].addr = ENTRYPOINT_SENTINEL;
traversal_stack[stack_ptr].dist = -FLT_MAX;
node_addr = kernel_tex_fetch(__object_node, object);
BVH_DEBUG_NEXT_INSTANCE();
}
}
#endif /* FEATURE(BVH_INSTANCING) */
} while (node_addr != ENTRYPOINT_SENTINEL);
#if BVH_FEATURE(BVH_INSTANCING)
if (stack_ptr >= 0) {
kernel_assert(object != OBJECT_NONE);
/* Instance pop. */
# if BVH_FEATURE(BVH_MOTION)
isect->t = bvh_instance_motion_pop(kg, object, ray, &P, &dir, &idir, isect->t, &ob_itfm);
# else
isect->t = bvh_instance_pop(kg, object, ray, &P, &dir, &idir, isect->t);
# endif
obvh_near_far_idx_calc(idir, &near_x, &near_y, &near_z, &far_x, &far_y, &far_z);
tfar = avxf(isect->t);
# if BVH_FEATURE(BVH_HAIR)
dir4 = avx3f(avxf(dir.x), avxf(dir.y), avxf(dir.z));
# endif
idir4 = avx3f(avxf(idir.x), avxf(idir.y), avxf(idir.z));
# ifdef __KERNEL_AVX2__
P_idir = P * idir;
P_idir4 = avx3f(P_idir.x, P_idir.y, P_idir.z);
# endif
# if BVH_FEATURE(BVH_HAIR) || !defined(__KERNEL_AVX2__)
org4 = avx3f(avxf(P.x), avxf(P.y), avxf(P.z));
# endif
object = OBJECT_NONE;
node_addr = traversal_stack[stack_ptr].addr;
node_dist = traversal_stack[stack_ptr].dist;
--stack_ptr;
}
#endif /* FEATURE(BVH_INSTANCING) */
} while (node_addr != ENTRYPOINT_SENTINEL);
return (isect->prim != PRIM_NONE);
}
#undef NODE_INTERSECT