forked from bartvdbraak/blender
ebc653463d
* Fix missing update when editing objects with emission materials. * Fix preview pass rendering set to 1 not showing full resolution. * Fix CUDA runtime compiling failing due to missing cache directory. * Use settings from first render layer for visibility and material override. And a bunch of incomplete and still disabled code mostly related to closure sampling.
156 lines
3.9 KiB
C++
156 lines
3.9 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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typedef struct LightSample {
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float3 P;
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float3 Ng;
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int object;
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int prim;
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int shader;
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float weight;
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} LightSample;
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/* Point Light */
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__device void point_light_sample(KernelGlobals *kg, int point,
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float randu, float randv, float3 P, LightSample *ls)
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{
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float4 f = kernel_tex_fetch(__light_point, point);
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ls->P = make_float3(f.x, f.y, f.z);
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ls->Ng = normalize(ls->P - P);
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ls->shader = __float_as_int(f.w);
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ls->object = ~0;
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ls->prim = ~0;
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}
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__device float point_light_pdf(KernelGlobals *kg, float t)
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{
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return t*t*kernel_data.integrator.pdf_lights;
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}
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/* Triangle Light */
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__device void triangle_light_sample(KernelGlobals *kg, int prim, int object,
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float randu, float randv, LightSample *ls)
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{
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/* triangle, so get position, normal, shader */
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ls->P = triangle_sample_MT(kg, prim, randu, randv);
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ls->Ng = triangle_normal_MT(kg, prim, &ls->shader);
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ls->object = object;
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ls->prim = prim;
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#ifdef __INSTANCING__
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/* instance transform */
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if(ls->object >= 0) {
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object_position_transform(kg, ls->object, &ls->P);
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object_normal_transform(kg, ls->object, &ls->Ng);
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}
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#endif
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}
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__device float triangle_light_pdf(KernelGlobals *kg,
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const float3 Ng, const float3 I, float t)
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{
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float cos_pi = fabsf(dot(Ng, I));
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if(cos_pi == 0.0f)
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return 0.0f;
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return (t*t*kernel_data.integrator.pdf_triangles)/cos_pi;
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}
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/* Light Distribution */
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__device int light_distribution_sample(KernelGlobals *kg, float randt)
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{
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/* this is basically std::upper_bound as used by pbrt, to find a point light or
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triangle to emit from, proportional to area. a good improvement would be to
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also sample proportional to power, though it's not so well defined with
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OSL shaders. */
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int first = 0;
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int len = kernel_data.integrator.num_distribution + 1;
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while(len > 0) {
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int half_len = len >> 1;
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int middle = first + half_len;
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if(randt < kernel_tex_fetch(__light_distribution, middle).x) {
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len = half_len;
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}
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else {
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first = middle + 1;
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len = len - half_len - 1;
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}
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}
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first = max(0, first-1);
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kernel_assert(first >= 0 && first < kernel_data.integrator.num_distribution);
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return first;
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}
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/* Generic Light */
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__device void light_sample(KernelGlobals *kg, float randt, float randu, float randv, float3 P, LightSample *ls)
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{
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/* sample index */
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int index = light_distribution_sample(kg, randt);
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/* fetch light data */
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float4 l = kernel_tex_fetch(__light_distribution, index);
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int prim = __float_as_int(l.y);
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ls->weight = l.z;
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if(prim >= 0) {
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int object = __float_as_int(l.w);
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triangle_light_sample(kg, prim, object, randu, randv, ls);
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}
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else {
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int point = -prim-1;
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point_light_sample(kg, point, randu, randv, P, ls);
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}
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}
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__device float light_sample_pdf(KernelGlobals *kg, LightSample *ls, float3 I, float t)
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{
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float pdf;
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if(ls->prim != ~0)
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pdf = triangle_light_pdf(kg, ls->Ng, I, t);
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else
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pdf = point_light_pdf(kg, t);
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return pdf;
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}
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__device void light_select(KernelGlobals *kg, int index, float randu, float randv, float3 P, LightSample *ls)
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{
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point_light_sample(kg, index, randu, randv, P, ls);
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}
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__device float light_select_pdf(KernelGlobals *kg, LightSample *ls, float3 I, float t)
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{
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return point_light_pdf(kg, t);
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}
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CCL_NAMESPACE_END
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