forked from bartvdbraak/blender
d5b679253a
* Sun, area and point lights with size now supported * Cast shadow option to disable shadow casting for lamps * Emission strength of materials tweaked such that setting strength to 1.0 basically makes the material "shadeless" in that the value of the color input will be the resulting color in the image.
140 lines
3.5 KiB
C
140 lines
3.5 KiB
C
/*
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* Copyright 2011, Blender Foundation.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*/
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CCL_NAMESPACE_BEGIN
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/* Direction Emission */
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__device float3 direct_emissive_eval(KernelGlobals *kg, float rando,
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LightSample *ls, float u, float v, float3 I)
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{
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/* setup shading at emitter */
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ShaderData sd;
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shader_setup_from_sample(kg, &sd, ls->P, ls->Ng, I, ls->shader, ls->object, ls->prim, u, v);
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ls->Ng = sd.Ng;
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/* no path flag, we're evaluating this for all closures. that's weak but
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we'd have to do multiple evaluations otherwise */
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shader_eval_surface(kg, &sd, rando, 0);
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float3 eval;
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/* evaluate emissive closure */
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if(sd.flag & SD_EMISSION)
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eval = shader_emissive_eval(kg, &sd);
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else
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eval = make_float3(0.0f, 0.0f, 0.0f);
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shader_release(kg, &sd);
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return eval;
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}
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__device bool direct_emission(KernelGlobals *kg, ShaderData *sd, int lindex,
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float randt, float rando, float randu, float randv, Ray *ray, float3 *eval)
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{
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LightSample ls;
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#ifdef __MULTI_LIGHT__
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if(lindex != -1) {
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/* sample position on a specified light */
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light_select(kg, lindex, randu, randv, sd->P, &ls);
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}
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else
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#endif
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{
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/* sample a light and position on int */
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light_sample(kg, randt, randu, randv, sd->P, &ls);
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}
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/* compute pdf */
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float pdf = light_sample_pdf(kg, &ls, -ls.D, ls.t);
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/* evaluate closure */
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*eval = direct_emissive_eval(kg, rando, &ls, randu, randv, -ls.D);
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if(is_zero(*eval) || pdf == 0.0f)
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return false;
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/* todo: use visbility flag to skip lights */
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/* evaluate BSDF at shading point */
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float bsdf_pdf;
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float3 bsdf_eval = shader_bsdf_eval(kg, sd, ls.D, &bsdf_pdf);
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*eval *= bsdf_eval/pdf;
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if(is_zero(*eval))
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return false;
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if(ls.prim != ~0) {
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/* multiple importance sampling */
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float mis_weight = power_heuristic(pdf, bsdf_pdf);
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*eval *= mis_weight;
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}
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/* todo: clean up these weights */
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else if(ls.shader & SHADER_AREA_LIGHT)
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*eval *= 0.25f; /* area lamp */
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else if(ls.t != FLT_MAX)
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*eval *= 0.25f*M_1_PI_F; /* point lamp */
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if(ls.shader & SHADER_CAST_SHADOW) {
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/* setup ray */
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ray->P = ray_offset(sd->P, sd->Ng);
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if(ls.t == FLT_MAX) {
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/* distant light */
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ray->D = ls.D;
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ray->t = ls.t;
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}
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else {
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/* other lights, avoid self-intersection */
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ray->D = ray_offset(ls.P, ls.Ng) - ray->P;
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ray->D = normalize_len(ray->D, &ray->t);
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}
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}
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else {
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/* signal to not cast shadow ray */
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ray->t = 0.0f;
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}
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return true;
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}
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/* Indirect Emission */
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__device float3 indirect_emission(KernelGlobals *kg, ShaderData *sd, float t, int path_flag, float bsdf_pdf)
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{
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/* evaluate emissive closure */
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float3 L = shader_emissive_eval(kg, sd);
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if(!(path_flag & PATH_RAY_SINGULAR) && (sd->flag & SD_SAMPLE_AS_LIGHT)) {
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/* multiple importance sampling */
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float pdf = triangle_light_pdf(kg, sd->Ng, sd->I, t);
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float mis_weight = power_heuristic(bsdf_pdf, pdf);
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return L*mis_weight;
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}
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return L;
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}
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CCL_NAMESPACE_END
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