blender/intern/cycles/kernel/split/kernel_indirect_background.h
Sergey Sharybin d14e39622a Cycles: First implementation of shadow catcher
It uses an idea of accumulating all possible light reachable across the
light path (without taking shadow blocked into account) and accumulating
total shaded light across the path. Dividing second figure by first one
seems to be giving good estimate of the shadow.

In fact, to my knowledge, it's something really similar to what is
happening in the denoising branch, so we are aligned here which is good.

The workflow is following:

- Create an object which matches real-life object on which shadow is
  to be catched.

- Create approximate similar material on that object.

  This is needed to make indirect light properly affecting CG objects
  in the scene.

- Mark object as Shadow Catcher in the Object properties.

Ideally, after doing that it will be possible to render the image and
simply alpha-over it on top of real footage.
2017-03-27 10:46:03 +02:00

83 lines
2.8 KiB
C

/*
* Copyright 2011-2017 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.
*/
CCL_NAMESPACE_BEGIN
ccl_device void kernel_indirect_background(KernelGlobals *kg)
{
ccl_global char *ray_state = kernel_split_state.ray_state;
int thread_index = ccl_global_id(1) * ccl_global_size(0) + ccl_global_id(0);
int ray_index;
if(kernel_data.integrator.ao_bounces) {
ray_index = get_ray_index(kg, thread_index,
QUEUE_ACTIVE_AND_REGENERATED_RAYS,
kernel_split_state.queue_data,
kernel_split_params.queue_size,
0);
if(ray_index != QUEUE_EMPTY_SLOT) {
if(IS_STATE(ray_state, ray_index, RAY_ACTIVE)) {
ccl_global PathState *state = &kernel_split_state.path_state[ray_index];
if(state->bounce > kernel_data.integrator.ao_bounces) {
ASSIGN_RAY_STATE(ray_state, ray_index, RAY_UPDATE_BUFFER);
}
}
}
}
ray_index = get_ray_index(kg, thread_index,
QUEUE_HITBG_BUFF_UPDATE_TOREGEN_RAYS,
kernel_split_state.queue_data,
kernel_split_params.queue_size,
0);
if(ray_index == QUEUE_EMPTY_SLOT) {
return;
}
ccl_global PathState *state = &kernel_split_state.path_state[ray_index];
PathRadiance *L = &kernel_split_state.path_radiance[ray_index];
ccl_global Ray *ray = &kernel_split_state.ray[ray_index];
ccl_global float3 *throughput = &kernel_split_state.throughput[ray_index];
ccl_global float *L_transparent = &kernel_split_state.L_transparent[ray_index];
if(IS_STATE(ray_state, ray_index, RAY_HIT_BACKGROUND)) {
/* eval background shader if nothing hit */
if(kernel_data.background.transparent && (state->flag & PATH_RAY_CAMERA)) {
*L_transparent = (*L_transparent) + average((*throughput));
#ifdef __PASSES__
if(!(kernel_data.film.pass_flag & PASS_BACKGROUND))
#endif
ASSIGN_RAY_STATE(ray_state, ray_index, RAY_UPDATE_BUFFER);
}
if(IS_STATE(ray_state, ray_index, RAY_HIT_BACKGROUND)) {
#ifdef __BACKGROUND__
/* sample background shader */
float3 L_background = indirect_background(kg, &kernel_split_state.sd_DL_shadow[ray_index], state, ray);
path_radiance_accum_background(L, state, (*throughput), L_background);
#endif
ASSIGN_RAY_STATE(ray_state, ray_index, RAY_UPDATE_BUFFER);
}
}
}
CCL_NAMESPACE_END