blender/intern/cycles/kernel/kernel_emission.h
Brecht Van Lommel 01e22d1b9f Cycles: more code refactoring to rename things internally as well. Also change
property name back so we keep compatibility.
2013-08-23 14:34:34 +00:00

267 lines
7.2 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 */
__device_noinline float3 direct_emissive_eval(KernelGlobals *kg, float rando,
LightSample *ls, float u, float v, float3 I, differential3 dI, float t, float time, int bounce)
{
/* setup shading at emitter */
ShaderData sd;
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;
#ifdef __CAMERA_MOTION__
ray.time = time;
#endif
shader_setup_from_background(kg, &sd, &ray, bounce+1);
eval = shader_eval_background(kg, &sd, 0, SHADER_CONTEXT_EMISSION);
}
else
#endif
{
#ifdef __HAIR__
if(ls->type == LIGHT_STRAND)
shader_setup_from_sample(kg, &sd, ls->P, ls->Ng, I, ls->shader, ls->object, ls->prim, u, v, t, time, bounce+1, ls->prim);
else
#endif
shader_setup_from_sample(kg, &sd, ls->P, ls->Ng, I, ls->shader, ls->object, ls->prim, u, v, t, time, bounce+1, ~0);
ls->Ng = 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, rando, 0, SHADER_CONTEXT_EMISSION);
/* evaluate emissive closure */
if(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;
}
__device_noinline bool direct_emission(KernelGlobals *kg, ShaderData *sd, int lindex,
float randt, float rando, float randu, float randv, Ray *ray, BsdfEval *eval,
bool *is_lamp, int bounce)
{
LightSample ls;
#ifdef __BRANCHED_PATH__
if(lindex != -1) {
/* sample position on a specified light */
light_select(kg, lindex, randu, randv, sd->P, &ls);
}
else
#endif
{
/* sample a light and position on int */
light_sample(kg, randt, randu, randv, sd->time, sd->P, &ls);
}
if(ls.pdf == 0.0f)
return false;
/* todo: implement */
differential3 dD = differential3_zero();
/* evaluate closure */
float3 light_eval = direct_emissive_eval(kg, rando, &ls, randu, randv, -ls.D, dD, ls.t, sd->time, bounce);
if(is_zero(light_eval))
return false;
/* evaluate BSDF at shading point */
float bsdf_pdf;
shader_bsdf_eval(kg, sd, ls.D, eval, &bsdf_pdf);
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);
}
#endif
if(bsdf_eval_is_zero(eval))
return false;
if(ls.shader & SHADER_CAST_SHADOW) {
/* setup ray */
bool transmit = (dot(sd->Ng, ls.D) < 0.0f);
ray->P = ray_offset(sd->P, (transmit)? -sd->Ng: 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 = 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 == ~0 && ls.type != LIGHT_BACKGROUND);
return true;
}
/* Indirect Primitive Emission */
__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) && (sd->flag & SD_USE_MIS) && (sd->segment == ~0)) {
#else
if(!(path_flag & PATH_RAY_MIS_SKIP) && (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, sd->Ng, sd->I, t);
float mis_weight = power_heuristic(bsdf_pdf, pdf);
return L*mis_weight;
}
return L;
}
/* Indirect Lamp Emission */
__device_noinline bool indirect_lamp_emission(KernelGlobals *kg, Ray *ray, int path_flag, float bsdf_pdf, float randt, float3 *emission, int bounce)
{
LightSample ls;
int lamp = lamp_light_eval_sample(kg, randt);
if(lamp == ~0)
return false;
if(!lamp_light_eval(kg, lamp, ray->P, ray->D, ray->t, &ls))
return false;
#ifdef __PASSES__
/* use visibility flag to skip lights */
if(ls.shader & SHADER_EXCLUDE_ANY) {
if(((ls.shader & SHADER_EXCLUDE_DIFFUSE) && (path_flag & PATH_RAY_DIFFUSE)) ||
((ls.shader & SHADER_EXCLUDE_GLOSSY) && (path_flag & PATH_RAY_GLOSSY)) ||
((ls.shader & SHADER_EXCLUDE_TRANSMIT) && (path_flag & PATH_RAY_TRANSMIT)))
return false;
}
#endif
/* todo: missing texture coordinates */
float u = 0.0f;
float v = 0.0f;
float3 L = direct_emissive_eval(kg, 0.0f, &ls, u, v, -ray->D, ray->dD, ls.t, ray->time, bounce);
if(!(path_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(bsdf_pdf, ls.pdf);
L *= mis_weight;
}
*emission = L;
return true;
}
/* Indirect Background */
__device_noinline float3 indirect_background(KernelGlobals *kg, Ray *ray, int path_flag, float bsdf_pdf, int bounce)
{
#ifdef __BACKGROUND__
int shader = kernel_data.background.shader;
/* use visibility flag to skip lights */
if(shader & SHADER_EXCLUDE_ANY) {
if(((shader & SHADER_EXCLUDE_DIFFUSE) && (path_flag & PATH_RAY_DIFFUSE)) ||
((shader & SHADER_EXCLUDE_GLOSSY) && (path_flag & PATH_RAY_GLOSSY)) ||
((shader & SHADER_EXCLUDE_TRANSMIT) && (path_flag & PATH_RAY_TRANSMIT)) ||
((shader & SHADER_EXCLUDE_CAMERA) && (path_flag & PATH_RAY_CAMERA)))
return make_float3(0.0f, 0.0f, 0.0f);
}
/* evaluate background closure */
ShaderData sd;
shader_setup_from_background(kg, &sd, ray, bounce+1);
float3 L = shader_eval_background(kg, &sd, path_flag, SHADER_CONTEXT_EMISSION);
#ifdef __BACKGROUND_MIS__
/* check if background light exists or if we should skip pdf */
int res = kernel_data.integrator.pdf_background_res;
if(!(path_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->D);
float mis_weight = power_heuristic(bsdf_pdf, pdf);
return L*mis_weight;
}
#endif
return L;
#else
return make_float3(0.8f, 0.8f, 0.8f);
#endif
}
CCL_NAMESPACE_END