blender/intern/cycles/kernel/bvh/bvh_traversal.h
Brecht Van Lommel 2c41c8e94f Cycles: internal refactoring to make thick/ribbon curve separate primitives
Also removing the curve system manager which only stored a few curve intersection
settings. These are all changes towards making shape and subdivision settings
per-object instead of per-scene, but there is more work to do here.

Ref T73778

Depends on D8013

Maniphest Tasks: T73778

Differential Revision: https://developer.blender.org/D8014
2020-06-22 13:28:01 +02:00

240 lines
7.9 KiB
C

/*
* Adapted from code Copyright 2009-2010 NVIDIA Corporation,
* and code copyright 2009-2012 Intel Corporation
*
* Modifications 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.
*/
#if BVH_FEATURE(BVH_HAIR)
# define NODE_INTERSECT bvh_node_intersect
#else
# define NODE_INTERSECT bvh_aligned_node_intersect
#endif
/* 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_HAIR: hair curve rendering
* BVH_MOTION: motion blur rendering
*/
ccl_device_noinline bool BVH_FUNCTION_FULL_NAME(BVH)(KernelGlobals *kg,
const Ray *ray,
Intersection *isect,
const uint visibility)
{
/* todo:
* - test if pushing distance on the stack helps (for non shadow rays)
* - separate version for shadow rays
* - likely and unlikely for if() statements
* - test restrict attribute for pointers
*/
/* traversal stack in CUDA thread-local memory */
int traversal_stack[BVH_STACK_SIZE];
traversal_stack[0] = ENTRYPOINT_SENTINEL;
/* traversal variables in registers */
int stack_ptr = 0;
int node_addr = kernel_data.bvh.root;
/* 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();
/* traversal loop */
do {
do {
/* traverse internal nodes */
while (node_addr >= 0 && node_addr != ENTRYPOINT_SENTINEL) {
int node_addr_child1, traverse_mask;
float dist[2];
float4 cnodes = kernel_tex_fetch(__bvh_nodes, node_addr + 0);
{
traverse_mask = NODE_INTERSECT(kg,
P,
#if BVH_FEATURE(BVH_HAIR)
dir,
#endif
idir,
isect->t,
node_addr,
visibility,
dist);
}
node_addr = __float_as_int(cnodes.z);
node_addr_child1 = __float_as_int(cnodes.w);
if (traverse_mask == 3) {
/* Both children were intersected, push the farther one. */
bool is_closest_child1 = (dist[1] < dist[0]);
if (is_closest_child1) {
int tmp = node_addr;
node_addr = node_addr_child1;
node_addr_child1 = tmp;
}
++stack_ptr;
kernel_assert(stack_ptr < BVH_STACK_SIZE);
traversal_stack[stack_ptr] = node_addr_child1;
}
else {
/* One child was intersected. */
if (traverse_mask == 2) {
node_addr = node_addr_child1;
}
else if (traverse_mask == 0) {
/* Neither child was intersected. */
node_addr = traversal_stack[stack_ptr];
--stack_ptr;
}
}
BVH_DEBUG_NEXT_NODE();
}
/* if node is leaf, fetch triangle list */
if (node_addr < 0) {
float4 leaf = kernel_tex_fetch(__bvh_leaf_nodes, (-node_addr - 1));
int prim_addr = __float_as_int(leaf.x);
if (prim_addr >= 0) {
const int prim_addr2 = __float_as_int(leaf.y);
const uint type = __float_as_int(leaf.w);
/* pop */
node_addr = traversal_stack[stack_ptr];
--stack_ptr;
/* primitive intersection */
switch (type & PRIMITIVE_ALL) {
case PRIMITIVE_TRIANGLE: {
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)) {
/* shadow ray early termination */
if (visibility & PATH_RAY_SHADOW_OPAQUE)
return true;
}
}
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)) {
/* 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_THICK:
case PRIMITIVE_MOTION_CURVE_THICK:
case PRIMITIVE_CURVE_RIBBON:
case PRIMITIVE_MOTION_CURVE_RIBBON: {
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));
const bool hit = curve_intersect(
kg, isect, P, dir, visibility, object, prim_addr, ray->time, curve_type);
if (hit) {
/* shadow ray early termination */
if (visibility & PATH_RAY_SHADOW_OPAQUE)
return true;
}
}
break;
}
#endif /* BVH_FEATURE(BVH_HAIR) */
}
}
else {
/* instance push */
object = kernel_tex_fetch(__prim_object, -prim_addr - 1);
#if BVH_FEATURE(BVH_MOTION)
isect->t = bvh_instance_motion_push(
kg, object, ray, &P, &dir, &idir, isect->t, &ob_itfm);
#else
isect->t = bvh_instance_push(kg, object, ray, &P, &dir, &idir, isect->t);
#endif
++stack_ptr;
kernel_assert(stack_ptr < BVH_STACK_SIZE);
traversal_stack[stack_ptr] = ENTRYPOINT_SENTINEL;
node_addr = kernel_tex_fetch(__object_node, object);
BVH_DEBUG_NEXT_INSTANCE();
}
}
} while (node_addr != ENTRYPOINT_SENTINEL);
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
object = OBJECT_NONE;
node_addr = traversal_stack[stack_ptr];
--stack_ptr;
}
} while (node_addr != ENTRYPOINT_SENTINEL);
return (isect->prim != PRIM_NONE);
}
ccl_device_inline bool BVH_FUNCTION_NAME(KernelGlobals *kg,
const Ray *ray,
Intersection *isect,
const uint visibility)
{
return BVH_FUNCTION_FULL_NAME(BVH)(kg, ray, isect, visibility);
}
#undef BVH_FUNCTION_NAME
#undef BVH_FUNCTION_FEATURES
#undef NODE_INTERSECT