blender/intern/cycles/kernel/kernel_emission.h

311 lines
9.0 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.
*/
CCL_NAMESPACE_BEGIN
/* Direction Emission */
ccl_device_noinline float3 direct_emissive_eval(KernelGlobals *kg,
LightSample *ls, float3 I, differential3 dI, float t, float time, int bounce, int transparent_bounce
#ifdef __SPLIT_KERNEL__
,ShaderData *sd_input
#endif
)
{
/* setup shading at emitter */
#ifdef __SPLIT_KERNEL__
ShaderData *sd = sd_input;
#else
ShaderData sd_object;
ShaderData *sd = &sd_object;
#endif
float3 eval;
#ifdef __BACKGROUND_MIS__
if(ls->type == LIGHT_BACKGROUND) {
Ray ray;
ray.D = ls->D;
ray.P = ls->P;
ray.t = 1.0f;
#ifdef __OBJECT_MOTION__
ray.time = time;
#endif
ray.dP = differential3_zero();
ray.dD = dI;
shader_setup_from_background(kg, sd, &ray, bounce+1, transparent_bounce);
eval = shader_eval_background(kg, sd, 0, SHADER_CONTEXT_EMISSION);
}
else
#endif
{
shader_setup_from_sample(kg, sd, ls->P, ls->Ng, I, ls->shader, ls->object, ls->prim, ls->u, ls->v, t, time, bounce+1, transparent_bounce);
ls->Ng = ccl_fetch(sd, Ng);
/* no path flag, we're evaluating this for all closures. that's weak but
* we'd have to do multiple evaluations otherwise */
shader_eval_surface(kg, sd, 0.0f, 0, SHADER_CONTEXT_EMISSION);
/* evaluate emissive closure */
if(ccl_fetch(sd, flag) & SD_EMISSION)
eval = shader_emissive_eval(kg, sd);
else
eval = make_float3(0.0f, 0.0f, 0.0f);
}
eval *= ls->eval_fac;
return eval;
}
ccl_device_noinline bool direct_emission(KernelGlobals *kg, ShaderData *sd,
LightSample *ls, Ray *ray, BsdfEval *eval, bool *is_lamp,
int bounce, int transparent_bounce
#ifdef __SPLIT_KERNEL__
, ShaderData *sd_DL
#endif
)
{
if(ls->pdf == 0.0f)
return false;
/* todo: implement */
differential3 dD = differential3_zero();
/* evaluate closure */
float3 light_eval = direct_emissive_eval(kg, ls, -ls->D, dD, ls->t, ccl_fetch(sd, time),
bounce,
transparent_bounce
#ifdef __SPLIT_KERNEL__
,sd_DL
#endif
);
if(is_zero(light_eval))
return false;
/* evaluate BSDF at shading point */
float bsdf_pdf;
#ifdef __VOLUME__
if(ccl_fetch(sd, prim) != PRIM_NONE)
shader_bsdf_eval(kg, sd, ls->D, eval, &bsdf_pdf);
else
shader_volume_phase_eval(kg, sd, ls->D, eval, &bsdf_pdf);
#else
shader_bsdf_eval(kg, sd, ls->D, eval, &bsdf_pdf);
#endif
if(ls->shader & SHADER_USE_MIS) {
/* multiple importance sampling */
float mis_weight = power_heuristic(ls->pdf, bsdf_pdf);
light_eval *= mis_weight;
}
bsdf_eval_mul(eval, light_eval/ls->pdf);
#ifdef __PASSES__
/* use visibility flag to skip lights */
if(ls->shader & SHADER_EXCLUDE_ANY) {
if(ls->shader & SHADER_EXCLUDE_DIFFUSE)
eval->diffuse = make_float3(0.0f, 0.0f, 0.0f);
if(ls->shader & SHADER_EXCLUDE_GLOSSY)
eval->glossy = make_float3(0.0f, 0.0f, 0.0f);
if(ls->shader & SHADER_EXCLUDE_TRANSMIT)
eval->transmission = make_float3(0.0f, 0.0f, 0.0f);
if(ls->shader & SHADER_EXCLUDE_SCATTER)
eval->scatter = make_float3(0.0f, 0.0f, 0.0f);
}
#endif
if(bsdf_eval_is_zero(eval))
return false;
if(ls->shader & SHADER_CAST_SHADOW) {
/* setup ray */
bool transmit = (dot(ccl_fetch(sd, Ng), ls->D) < 0.0f);
ray->P = ray_offset(ccl_fetch(sd, P), (transmit)? -ccl_fetch(sd, Ng): ccl_fetch(sd, Ng));
if(ls->t == FLT_MAX) {
/* distant light */
ray->D = ls->D;
ray->t = ls->t;
}
else {
/* other lights, avoid self-intersection */
ray->D = ray_offset(ls->P, ls->Ng) - ray->P;
ray->D = normalize_len(ray->D, &ray->t);
}
ray->dP = ccl_fetch(sd, dP);
ray->dD = differential3_zero();
}
else {
/* signal to not cast shadow ray */
ray->t = 0.0f;
}
/* return if it's a lamp for shadow pass */
*is_lamp = (ls->prim == PRIM_NONE && ls->type != LIGHT_BACKGROUND);
return true;
}
/* Indirect Primitive Emission */
ccl_device_noinline float3 indirect_primitive_emission(KernelGlobals *kg, ShaderData *sd, float t, int path_flag, float bsdf_pdf)
{
/* evaluate emissive closure */
float3 L = shader_emissive_eval(kg, sd);
#ifdef __HAIR__
if(!(path_flag & PATH_RAY_MIS_SKIP) && (ccl_fetch(sd, flag) & SD_USE_MIS) && (ccl_fetch(sd, type) & PRIMITIVE_ALL_TRIANGLE))
#else
if(!(path_flag & PATH_RAY_MIS_SKIP) && (ccl_fetch(sd, flag) & SD_USE_MIS))
#endif
{
/* multiple importance sampling, get triangle light pdf,
* and compute weight with respect to BSDF pdf */
float pdf = triangle_light_pdf(kg, ccl_fetch(sd, Ng), ccl_fetch(sd, I), t);
float mis_weight = power_heuristic(bsdf_pdf, pdf);
return L*mis_weight;
}
return L;
}
/* Indirect Lamp Emission */
ccl_device_noinline bool indirect_lamp_emission(KernelGlobals *kg, PathState *state, Ray *ray, float3 *emission
#ifdef __SPLIT_KERNEL__
,ShaderData *sd
#endif
)
{
bool hit_lamp = false;
*emission = make_float3(0.0f, 0.0f, 0.0f);
for(int lamp = 0; lamp < kernel_data.integrator.num_all_lights; lamp++) {
LightSample ls;
if(!lamp_light_eval(kg, lamp, ray->P, ray->D, ray->t, &ls))
continue;
#ifdef __PASSES__
/* use visibility flag to skip lights */
if(ls.shader & SHADER_EXCLUDE_ANY) {
if(((ls.shader & SHADER_EXCLUDE_DIFFUSE) && (state->flag & PATH_RAY_DIFFUSE)) ||
((ls.shader & SHADER_EXCLUDE_GLOSSY) &&
((state->flag & (PATH_RAY_GLOSSY|PATH_RAY_REFLECT)) == (PATH_RAY_GLOSSY|PATH_RAY_REFLECT))) ||
((ls.shader & SHADER_EXCLUDE_TRANSMIT) && (state->flag & PATH_RAY_TRANSMIT)) ||
((ls.shader & SHADER_EXCLUDE_SCATTER) && (state->flag & PATH_RAY_VOLUME_SCATTER)))
continue;
}
#endif
float3 L = direct_emissive_eval(kg, &ls, -ray->D, ray->dD, ls.t, ray->time,
state->bounce,
state->transparent_bounce
#ifdef __SPLIT_KERNEL__
,sd
#endif
);
#ifdef __VOLUME__
if(state->volume_stack[0].shader != SHADER_NONE) {
/* shadow attenuation */
Ray volume_ray = *ray;
volume_ray.t = ls.t;
float3 volume_tp = make_float3(1.0f, 1.0f, 1.0f);
kernel_volume_shadow(kg, state, &volume_ray, &volume_tp);
L *= volume_tp;
}
#endif
if(!(state->flag & PATH_RAY_MIS_SKIP)) {
/* multiple importance sampling, get regular light pdf,
* and compute weight with respect to BSDF pdf */
float mis_weight = power_heuristic(state->ray_pdf, ls.pdf);
L *= mis_weight;
}
*emission += L;
hit_lamp = true;
}
return hit_lamp;
}
/* Indirect Background */
ccl_device_noinline float3 indirect_background(KernelGlobals *kg, ccl_addr_space PathState *state, ccl_addr_space Ray *ray
#ifdef __SPLIT_KERNEL__
,ShaderData *sd_global
#endif
)
{
#ifdef __BACKGROUND__
int shader = kernel_data.background.surface_shader;
/* use visibility flag to skip lights */
if(shader & SHADER_EXCLUDE_ANY) {
if(((shader & SHADER_EXCLUDE_DIFFUSE) && (state->flag & PATH_RAY_DIFFUSE)) ||
((shader & SHADER_EXCLUDE_GLOSSY) &&
((state->flag & (PATH_RAY_GLOSSY|PATH_RAY_REFLECT)) == (PATH_RAY_GLOSSY|PATH_RAY_REFLECT))) ||
((shader & SHADER_EXCLUDE_TRANSMIT) && (state->flag & PATH_RAY_TRANSMIT)) ||
((shader & SHADER_EXCLUDE_CAMERA) && (state->flag & PATH_RAY_CAMERA)) ||
((shader & SHADER_EXCLUDE_SCATTER) && (state->flag & PATH_RAY_VOLUME_SCATTER)))
return make_float3(0.0f, 0.0f, 0.0f);
}
#ifdef __SPLIT_KERNEL__
/* evaluate background closure */
Ray priv_ray = *ray;
shader_setup_from_background(kg, sd_global, &priv_ray, state->bounce+1, state->transparent_bounce);
float3 L = shader_eval_background(kg, sd_global, state->flag, SHADER_CONTEXT_EMISSION);
#else
ShaderData sd;
shader_setup_from_background(kg, &sd, ray, state->bounce+1, state->transparent_bounce);
float3 L = shader_eval_background(kg, &sd, state->flag, SHADER_CONTEXT_EMISSION);
#endif
#ifdef __BACKGROUND_MIS__
/* check if background light exists or if we should skip pdf */
int res = kernel_data.integrator.pdf_background_res;
if(!(state->flag & PATH_RAY_MIS_SKIP) && res) {
/* multiple importance sampling, get background light pdf for ray
* direction, and compute weight with respect to BSDF pdf */
float pdf = background_light_pdf(kg, ray->P, ray->D);
float mis_weight = power_heuristic(state->ray_pdf, pdf);
return L*mis_weight;
}
#endif
return L;
#else
return make_float3(0.8f, 0.8f, 0.8f);
#endif
}
CCL_NAMESPACE_END