forked from bartvdbraak/blender
1204 lines
35 KiB
C
1204 lines
35 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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#ifdef __OSL__
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#include "osl_shader.h"
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#endif
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#include "kernel_differential.h"
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#include "kernel_montecarlo.h"
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#include "kernel_projection.h"
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#include "kernel_object.h"
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#include "kernel_triangle.h"
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#include "kernel_curve.h"
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#include "kernel_primitive.h"
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#include "kernel_projection.h"
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#include "kernel_random.h"
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#include "kernel_bvh.h"
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#include "kernel_accumulate.h"
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#include "kernel_camera.h"
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#include "kernel_shader.h"
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#include "kernel_light.h"
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#include "kernel_emission.h"
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#include "kernel_passes.h"
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#ifdef __SUBSURFACE__
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#include "kernel_subsurface.h"
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#endif
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CCL_NAMESPACE_BEGIN
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typedef struct PathState {
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int flag;
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int bounce;
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int diffuse_bounce;
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int glossy_bounce;
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int transmission_bounce;
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int transparent_bounce;
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} PathState;
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__device_inline void path_state_init(PathState *state)
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{
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state->flag = PATH_RAY_CAMERA|PATH_RAY_SINGULAR|PATH_RAY_MIS_SKIP;
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state->bounce = 0;
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state->diffuse_bounce = 0;
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state->glossy_bounce = 0;
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state->transmission_bounce = 0;
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state->transparent_bounce = 0;
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}
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__device_inline void path_state_next(KernelGlobals *kg, PathState *state, int label)
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{
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/* ray through transparent keeps same flags from previous ray and is
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* not counted as a regular bounce, transparent has separate max */
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if(label & LABEL_TRANSPARENT) {
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state->flag |= PATH_RAY_TRANSPARENT;
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state->transparent_bounce++;
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if(!kernel_data.integrator.transparent_shadows)
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state->flag |= PATH_RAY_MIS_SKIP;
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return;
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}
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state->bounce++;
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/* reflection/transmission */
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if(label & LABEL_REFLECT) {
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state->flag |= PATH_RAY_REFLECT;
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state->flag &= ~(PATH_RAY_TRANSMIT|PATH_RAY_CAMERA|PATH_RAY_TRANSPARENT);
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if(label & LABEL_DIFFUSE)
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state->diffuse_bounce++;
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else
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state->glossy_bounce++;
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}
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else {
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kernel_assert(label & LABEL_TRANSMIT);
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state->flag |= PATH_RAY_TRANSMIT;
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state->flag &= ~(PATH_RAY_REFLECT|PATH_RAY_CAMERA|PATH_RAY_TRANSPARENT);
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state->transmission_bounce++;
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}
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/* diffuse/glossy/singular */
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if(label & LABEL_DIFFUSE) {
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state->flag |= PATH_RAY_DIFFUSE;
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state->flag &= ~(PATH_RAY_GLOSSY|PATH_RAY_SINGULAR|PATH_RAY_MIS_SKIP);
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}
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else if(label & LABEL_GLOSSY) {
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state->flag |= PATH_RAY_GLOSSY;
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state->flag &= ~(PATH_RAY_DIFFUSE|PATH_RAY_SINGULAR|PATH_RAY_MIS_SKIP);
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}
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else {
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kernel_assert(label & LABEL_SINGULAR);
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state->flag |= PATH_RAY_GLOSSY|PATH_RAY_SINGULAR|PATH_RAY_MIS_SKIP;
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state->flag &= ~PATH_RAY_DIFFUSE;
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}
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}
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__device_inline uint path_state_ray_visibility(KernelGlobals *kg, PathState *state)
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{
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uint flag = state->flag;
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/* for visibility, diffuse/glossy are for reflection only */
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if(flag & PATH_RAY_TRANSMIT)
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flag &= ~(PATH_RAY_DIFFUSE|PATH_RAY_GLOSSY);
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/* for camera visibility, use render layer flags */
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if(flag & PATH_RAY_CAMERA)
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flag |= kernel_data.integrator.layer_flag;
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return flag;
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}
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__device_inline float path_state_terminate_probability(KernelGlobals *kg, PathState *state, const float3 throughput)
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{
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if(state->flag & PATH_RAY_TRANSPARENT) {
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/* transparent rays treated separately */
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if(state->transparent_bounce >= kernel_data.integrator.transparent_max_bounce)
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return 0.0f;
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else if(state->transparent_bounce <= kernel_data.integrator.transparent_min_bounce)
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return 1.0f;
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}
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else {
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/* other rays */
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if((state->bounce >= kernel_data.integrator.max_bounce) ||
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(state->diffuse_bounce >= kernel_data.integrator.max_diffuse_bounce) ||
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(state->glossy_bounce >= kernel_data.integrator.max_glossy_bounce) ||
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(state->transmission_bounce >= kernel_data.integrator.max_transmission_bounce))
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{
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return 0.0f;
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}
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else if(state->bounce <= kernel_data.integrator.min_bounce) {
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return 1.0f;
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}
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}
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/* probalistic termination */
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return average(throughput); /* todo: try using max here */
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}
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__device_inline bool shadow_blocked(KernelGlobals *kg, PathState *state, Ray *ray, float3 *shadow)
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{
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*shadow = make_float3(1.0f, 1.0f, 1.0f);
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if(ray->t == 0.0f)
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return false;
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Intersection isect;
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#ifdef __HAIR__
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bool result = scene_intersect(kg, ray, PATH_RAY_SHADOW_OPAQUE, &isect, NULL, 0.0f, 0.0f);
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#else
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bool result = scene_intersect(kg, ray, PATH_RAY_SHADOW_OPAQUE, &isect);
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#endif
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#ifdef __TRANSPARENT_SHADOWS__
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if(result && kernel_data.integrator.transparent_shadows) {
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/* transparent shadows work in such a way to try to minimize overhead
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* in cases where we don't need them. after a regular shadow ray is
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* cast we check if the hit primitive was potentially transparent, and
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* only in that case start marching. this gives on extra ray cast for
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* the cases were we do want transparency.
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*
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* also note that for this to work correct, multi close sampling must
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* be used, since we don't pass a random number to shader_eval_surface */
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if(shader_transparent_shadow(kg, &isect)) {
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float3 throughput = make_float3(1.0f, 1.0f, 1.0f);
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float3 Pend = ray->P + ray->D*ray->t;
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int bounce = state->transparent_bounce;
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for(;;) {
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if(bounce >= kernel_data.integrator.transparent_max_bounce) {
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return true;
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}
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else if(bounce >= kernel_data.integrator.transparent_min_bounce) {
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/* todo: get random number somewhere for probabilistic terminate */
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#if 0
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float probability = average(throughput);
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float terminate = 0.0f;
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if(terminate >= probability)
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return true;
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throughput /= probability;
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#endif
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}
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#ifdef __HAIR__
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if(!scene_intersect(kg, ray, PATH_RAY_SHADOW_TRANSPARENT, &isect, NULL, 0.0f, 0.0f)) {
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#else
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if(!scene_intersect(kg, ray, PATH_RAY_SHADOW_TRANSPARENT, &isect)) {
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#endif
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*shadow *= throughput;
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return false;
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}
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if(!shader_transparent_shadow(kg, &isect))
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return true;
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ShaderData sd;
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shader_setup_from_ray(kg, &sd, &isect, ray);
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shader_eval_surface(kg, &sd, 0.0f, PATH_RAY_SHADOW, SHADER_CONTEXT_SHADOW);
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throughput *= shader_bsdf_transparency(kg, &sd);
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ray->P = ray_offset(sd.P, -sd.Ng);
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if(ray->t != FLT_MAX)
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ray->D = normalize_len(Pend - ray->P, &ray->t);
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bounce++;
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}
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}
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}
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#endif
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return result;
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}
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__device float4 kernel_path_progressive(KernelGlobals *kg, RNG *rng, int sample, Ray ray, __global float *buffer)
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{
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/* initialize */
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PathRadiance L;
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float3 throughput = make_float3(1.0f, 1.0f, 1.0f);
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float L_transparent = 0.0f;
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path_radiance_init(&L, kernel_data.film.use_light_pass);
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float min_ray_pdf = FLT_MAX;
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float ray_pdf = 0.0f;
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#ifdef __LAMP_MIS__
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float ray_t = 0.0f;
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#endif
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PathState state;
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int rng_offset = PRNG_BASE_NUM;
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int num_samples = kernel_data.integrator.aa_samples;
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path_state_init(&state);
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/* path iteration */
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for(;; rng_offset += PRNG_BOUNCE_NUM) {
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/* intersect scene */
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Intersection isect;
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uint visibility = path_state_ray_visibility(kg, &state);
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#ifdef __HAIR__
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float difl = 0.0f, extmax = 0.0f;
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uint lcg_state = 0;
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if(kernel_data.bvh.have_curves) {
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if((kernel_data.cam.resolution == 1) && (state.flag & PATH_RAY_CAMERA)) {
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float3 pixdiff = ray.dD.dx + ray.dD.dy;
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/*pixdiff = pixdiff - dot(pixdiff, ray.D)*ray.D;*/
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difl = kernel_data.curve_kernel_data.minimum_width * len(pixdiff) * 0.5f;
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}
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extmax = kernel_data.curve_kernel_data.maximum_width;
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lcg_state = lcg_init(*rng + rng_offset + sample*0x51633e2d);
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}
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bool hit = scene_intersect(kg, &ray, visibility, &isect, &lcg_state, difl, extmax);
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#else
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bool hit = scene_intersect(kg, &ray, visibility, &isect);
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#endif
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#ifdef __LAMP_MIS__
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if(kernel_data.integrator.use_lamp_mis && !(state.flag & PATH_RAY_CAMERA)) {
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/* ray starting from previous non-transparent bounce */
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Ray light_ray;
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light_ray.P = ray.P - ray_t*ray.D;
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ray_t += isect.t;
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light_ray.D = ray.D;
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light_ray.t = ray_t;
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light_ray.time = ray.time;
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light_ray.dD = ray.dD;
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light_ray.dP = ray.dP;
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/* intersect with lamp */
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float light_t = path_rng_1D(kg, rng, sample, num_samples, rng_offset + PRNG_LIGHT);
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float3 emission;
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if(indirect_lamp_emission(kg, &light_ray, state.flag, ray_pdf, light_t, &emission))
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path_radiance_accum_emission(&L, throughput, emission, state.bounce);
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}
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#endif
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if(!hit) {
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/* eval background shader if nothing hit */
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if(kernel_data.background.transparent && (state.flag & PATH_RAY_CAMERA)) {
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L_transparent += average(throughput);
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#ifdef __PASSES__
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if(!(kernel_data.film.pass_flag & PASS_BACKGROUND))
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#endif
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break;
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}
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#ifdef __BACKGROUND__
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/* sample background shader */
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float3 L_background = indirect_background(kg, &ray, state.flag, ray_pdf);
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path_radiance_accum_background(&L, throughput, L_background, state.bounce);
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#endif
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break;
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}
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/* setup shading */
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ShaderData sd;
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shader_setup_from_ray(kg, &sd, &isect, &ray);
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float rbsdf = path_rng_1D(kg, rng, sample, num_samples, rng_offset + PRNG_BSDF);
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shader_eval_surface(kg, &sd, rbsdf, state.flag, SHADER_CONTEXT_MAIN);
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/* holdout */
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#ifdef __HOLDOUT__
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if((sd.flag & (SD_HOLDOUT|SD_HOLDOUT_MASK)) && (state.flag & PATH_RAY_CAMERA)) {
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if(kernel_data.background.transparent) {
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float3 holdout_weight;
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if(sd.flag & SD_HOLDOUT_MASK)
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holdout_weight = make_float3(1.0f, 1.0f, 1.0f);
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else
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holdout_weight = shader_holdout_eval(kg, &sd);
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/* any throughput is ok, should all be identical here */
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L_transparent += average(holdout_weight*throughput);
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}
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if(sd.flag & SD_HOLDOUT_MASK)
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break;
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}
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#endif
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/* holdout mask objects do not write data passes */
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kernel_write_data_passes(kg, buffer, &L, &sd, sample, state.flag, throughput);
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/* blurring of bsdf after bounces, for rays that have a small likelihood
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* of following this particular path (diffuse, rough glossy) */
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if(kernel_data.integrator.filter_glossy != FLT_MAX) {
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float blur_pdf = kernel_data.integrator.filter_glossy*min_ray_pdf;
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if(blur_pdf < 1.0f) {
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float blur_roughness = sqrtf(1.0f - blur_pdf)*0.5f;
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shader_bsdf_blur(kg, &sd, blur_roughness);
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}
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}
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#ifdef __EMISSION__
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/* emission */
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if(sd.flag & SD_EMISSION) {
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/* todo: is isect.t wrong here for transparent surfaces? */
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float3 emission = indirect_primitive_emission(kg, &sd, isect.t, state.flag, ray_pdf);
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path_radiance_accum_emission(&L, throughput, emission, state.bounce);
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}
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#endif
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/* path termination. this is a strange place to put the termination, it's
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* mainly due to the mixed in MIS that we use. gives too many unneeded
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* shader evaluations, only need emission if we are going to terminate */
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float probability = path_state_terminate_probability(kg, &state, throughput);
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if(probability == 0.0f) {
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break;
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}
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else if(probability != 1.0f) {
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float terminate = path_rng_1D(kg, rng, sample, num_samples, rng_offset + PRNG_TERMINATE);
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if(terminate >= probability)
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break;
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throughput /= probability;
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}
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#ifdef __SUBSURFACE__
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/* bssrdf scatter to a different location on the same object, replacing
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* the closures with a diffuse BSDF */
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if(sd.flag & SD_BSSRDF) {
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float bssrdf_probability;
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ShaderClosure *sc = subsurface_scatter_pick_closure(kg, &sd, &bssrdf_probability);
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/* modify throughput for picking bssrdf or bsdf */
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throughput *= bssrdf_probability;
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/* do bssrdf scatter step if we picked a bssrdf closure */
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if(sc) {
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uint lcg_state = lcg_init(*rng + rng_offset + sample*0x68bc21eb);
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subsurface_scatter_step(kg, &sd, state.flag, sc, &lcg_state, false);
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}
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}
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#endif
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#ifdef __AO__
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/* ambient occlusion */
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if(kernel_data.integrator.use_ambient_occlusion || (sd.flag & SD_AO)) {
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/* todo: solve correlation */
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float2 bsdf_uv = path_rng_2D(kg, rng, sample, num_samples, rng_offset + PRNG_BSDF_U);
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float bsdf_u = bsdf_uv.x;
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float bsdf_v = bsdf_uv.y;
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float ao_factor = kernel_data.background.ao_factor;
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float3 ao_N;
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float3 ao_bsdf = shader_bsdf_ao(kg, &sd, ao_factor, &ao_N);
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float3 ao_D;
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float ao_pdf;
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sample_cos_hemisphere(ao_N, bsdf_u, bsdf_v, &ao_D, &ao_pdf);
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if(dot(sd.Ng, ao_D) > 0.0f && ao_pdf != 0.0f) {
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Ray light_ray;
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float3 ao_shadow;
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light_ray.P = ray_offset(sd.P, sd.Ng);
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light_ray.D = ao_D;
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light_ray.t = kernel_data.background.ao_distance;
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#ifdef __OBJECT_MOTION__
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light_ray.time = sd.time;
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#endif
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light_ray.dP = sd.dP;
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light_ray.dD = differential3_zero();
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if(!shadow_blocked(kg, &state, &light_ray, &ao_shadow))
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path_radiance_accum_ao(&L, throughput, ao_bsdf, ao_shadow, state.bounce);
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}
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}
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#endif
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#ifdef __EMISSION__
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if(kernel_data.integrator.use_direct_light) {
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/* sample illumination from lights to find path contribution */
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if(sd.flag & SD_BSDF_HAS_EVAL) {
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float light_t = path_rng_1D(kg, rng, sample, num_samples, rng_offset + PRNG_LIGHT);
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#ifdef __MULTI_CLOSURE__
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float light_o = 0.0f;
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#else
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float light_o = path_rng_1D(kg, rng, sample, num_samples, rng_offset + PRNG_LIGHT_F);
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#endif
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float2 light_uv = path_rng_2D(kg, rng, sample, num_samples, rng_offset + PRNG_LIGHT_U);
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float light_u = light_uv.x;
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float light_v = light_uv.y;
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Ray light_ray;
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BsdfEval L_light;
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bool is_lamp;
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#ifdef __OBJECT_MOTION__
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light_ray.time = sd.time;
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#endif
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if(direct_emission(kg, &sd, -1, light_t, light_o, light_u, light_v, &light_ray, &L_light, &is_lamp)) {
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/* trace shadow ray */
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float3 shadow;
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if(!shadow_blocked(kg, &state, &light_ray, &shadow)) {
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/* accumulate */
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path_radiance_accum_light(&L, throughput, &L_light, shadow, 1.0f, state.bounce, is_lamp);
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}
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}
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}
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}
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#endif
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|
|
|
/* no BSDF? we can stop here */
|
|
if(!(sd.flag & SD_BSDF))
|
|
break;
|
|
|
|
/* sample BSDF */
|
|
float bsdf_pdf;
|
|
BsdfEval bsdf_eval;
|
|
float3 bsdf_omega_in;
|
|
differential3 bsdf_domega_in;
|
|
float2 bsdf_uv = path_rng_2D(kg, rng, sample, num_samples, rng_offset + PRNG_BSDF_U);
|
|
float bsdf_u = bsdf_uv.x;
|
|
float bsdf_v = bsdf_uv.y;
|
|
int label;
|
|
|
|
label = shader_bsdf_sample(kg, &sd, bsdf_u, bsdf_v, &bsdf_eval,
|
|
&bsdf_omega_in, &bsdf_domega_in, &bsdf_pdf);
|
|
|
|
if(bsdf_pdf == 0.0f || bsdf_eval_is_zero(&bsdf_eval))
|
|
break;
|
|
|
|
/* modify throughput */
|
|
path_radiance_bsdf_bounce(&L, &throughput, &bsdf_eval, bsdf_pdf, state.bounce, label);
|
|
|
|
/* set labels */
|
|
if(!(label & LABEL_TRANSPARENT)) {
|
|
ray_pdf = bsdf_pdf;
|
|
#ifdef __LAMP_MIS__
|
|
ray_t = 0.0f;
|
|
#endif
|
|
min_ray_pdf = fminf(bsdf_pdf, min_ray_pdf);
|
|
}
|
|
|
|
/* update path state */
|
|
path_state_next(kg, &state, label);
|
|
|
|
/* setup ray */
|
|
ray.P = ray_offset(sd.P, (label & LABEL_TRANSMIT)? -sd.Ng: sd.Ng);
|
|
ray.D = bsdf_omega_in;
|
|
|
|
if(state.bounce == 0)
|
|
ray.t -= sd.ray_length; /* clipping works through transparent */
|
|
else
|
|
ray.t = FLT_MAX;
|
|
|
|
#ifdef __RAY_DIFFERENTIALS__
|
|
ray.dP = sd.dP;
|
|
ray.dD = bsdf_domega_in;
|
|
#endif
|
|
}
|
|
|
|
float3 L_sum = path_radiance_sum(kg, &L);
|
|
|
|
#ifdef __CLAMP_SAMPLE__
|
|
path_radiance_clamp(&L, &L_sum, kernel_data.integrator.sample_clamp);
|
|
#endif
|
|
|
|
kernel_write_light_passes(kg, buffer, &L, sample);
|
|
|
|
return make_float4(L_sum.x, L_sum.y, L_sum.z, 1.0f - L_transparent);
|
|
}
|
|
|
|
#ifdef __NON_PROGRESSIVE__
|
|
|
|
__device void kernel_path_indirect(KernelGlobals *kg, RNG *rng, int sample, Ray ray, __global float *buffer,
|
|
float3 throughput, int num_samples, int num_total_samples,
|
|
float min_ray_pdf, float ray_pdf, PathState state, int rng_offset, PathRadiance *L)
|
|
{
|
|
#ifdef __LAMP_MIS__
|
|
float ray_t = 0.0f;
|
|
#endif
|
|
|
|
/* path iteration */
|
|
for(;; rng_offset += PRNG_BOUNCE_NUM) {
|
|
/* intersect scene */
|
|
Intersection isect;
|
|
uint visibility = path_state_ray_visibility(kg, &state);
|
|
#ifdef __HAIR__
|
|
bool hit = scene_intersect(kg, &ray, visibility, &isect, NULL, 0.0f, 0.0f);
|
|
#else
|
|
bool hit = scene_intersect(kg, &ray, visibility, &isect);
|
|
#endif
|
|
|
|
#ifdef __LAMP_MIS__
|
|
if(kernel_data.integrator.use_lamp_mis && !(state.flag & PATH_RAY_CAMERA)) {
|
|
/* ray starting from previous non-transparent bounce */
|
|
Ray light_ray;
|
|
|
|
light_ray.P = ray.P - ray_t*ray.D;
|
|
ray_t += isect.t;
|
|
light_ray.D = ray.D;
|
|
light_ray.t = ray_t;
|
|
light_ray.time = ray.time;
|
|
light_ray.dD = ray.dD;
|
|
light_ray.dP = ray.dP;
|
|
|
|
/* intersect with lamp */
|
|
float light_t = path_rng_1D(kg, rng, sample, num_total_samples, rng_offset + PRNG_LIGHT);
|
|
float3 emission;
|
|
|
|
if(indirect_lamp_emission(kg, &light_ray, state.flag, ray_pdf, light_t, &emission))
|
|
path_radiance_accum_emission(L, throughput, emission, state.bounce);
|
|
}
|
|
#endif
|
|
|
|
if(!hit) {
|
|
#ifdef __BACKGROUND__
|
|
/* sample background shader */
|
|
float3 L_background = indirect_background(kg, &ray, state.flag, ray_pdf);
|
|
path_radiance_accum_background(L, throughput, L_background, state.bounce);
|
|
#endif
|
|
|
|
break;
|
|
}
|
|
|
|
/* setup shading */
|
|
ShaderData sd;
|
|
shader_setup_from_ray(kg, &sd, &isect, &ray);
|
|
float rbsdf = path_rng_1D(kg, rng, sample, num_total_samples, rng_offset + PRNG_BSDF);
|
|
shader_eval_surface(kg, &sd, rbsdf, state.flag, SHADER_CONTEXT_INDIRECT);
|
|
shader_merge_closures(kg, &sd);
|
|
|
|
/* blurring of bsdf after bounces, for rays that have a small likelihood
|
|
* of following this particular path (diffuse, rough glossy) */
|
|
if(kernel_data.integrator.filter_glossy != FLT_MAX) {
|
|
float blur_pdf = kernel_data.integrator.filter_glossy*min_ray_pdf;
|
|
|
|
if(blur_pdf < 1.0f) {
|
|
float blur_roughness = sqrtf(1.0f - blur_pdf)*0.5f;
|
|
shader_bsdf_blur(kg, &sd, blur_roughness);
|
|
}
|
|
}
|
|
|
|
#ifdef __EMISSION__
|
|
/* emission */
|
|
if(sd.flag & SD_EMISSION) {
|
|
float3 emission = indirect_primitive_emission(kg, &sd, isect.t, state.flag, ray_pdf);
|
|
path_radiance_accum_emission(L, throughput, emission, state.bounce);
|
|
}
|
|
#endif
|
|
|
|
/* path termination. this is a strange place to put the termination, it's
|
|
* mainly due to the mixed in MIS that we use. gives too many unneeded
|
|
* shader evaluations, only need emission if we are going to terminate */
|
|
float probability = path_state_terminate_probability(kg, &state, throughput*num_samples);
|
|
|
|
if(probability == 0.0f) {
|
|
break;
|
|
}
|
|
else if(probability != 1.0f) {
|
|
float terminate = path_rng_1D(kg, rng, sample, num_total_samples, rng_offset + PRNG_TERMINATE);
|
|
|
|
if(terminate >= probability)
|
|
break;
|
|
|
|
throughput /= probability;
|
|
}
|
|
|
|
#ifdef __SUBSURFACE__
|
|
/* bssrdf scatter to a different location on the same object, replacing
|
|
* the closures with a diffuse BSDF */
|
|
if(sd.flag & SD_BSSRDF) {
|
|
float bssrdf_probability;
|
|
ShaderClosure *sc = subsurface_scatter_pick_closure(kg, &sd, &bssrdf_probability);
|
|
|
|
/* modify throughput for picking bssrdf or bsdf */
|
|
throughput *= bssrdf_probability;
|
|
|
|
/* do bssrdf scatter step if we picked a bssrdf closure */
|
|
if(sc) {
|
|
uint lcg_state = lcg_init(*rng + rng_offset + sample*0x68bc21eb);
|
|
subsurface_scatter_step(kg, &sd, state.flag, sc, &lcg_state, false);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#ifdef __AO__
|
|
/* ambient occlusion */
|
|
if(kernel_data.integrator.use_ambient_occlusion || (sd.flag & SD_AO)) {
|
|
/* todo: solve correlation */
|
|
float2 bsdf_uv = path_rng_2D(kg, rng, sample, num_total_samples, rng_offset + PRNG_BSDF_U);
|
|
float bsdf_u = bsdf_uv.x;
|
|
float bsdf_v = bsdf_uv.y;
|
|
|
|
float ao_factor = kernel_data.background.ao_factor;
|
|
float3 ao_N;
|
|
float3 ao_bsdf = shader_bsdf_ao(kg, &sd, ao_factor, &ao_N);
|
|
float3 ao_D;
|
|
float ao_pdf;
|
|
|
|
sample_cos_hemisphere(ao_N, bsdf_u, bsdf_v, &ao_D, &ao_pdf);
|
|
|
|
if(dot(sd.Ng, ao_D) > 0.0f && ao_pdf != 0.0f) {
|
|
Ray light_ray;
|
|
float3 ao_shadow;
|
|
|
|
light_ray.P = ray_offset(sd.P, sd.Ng);
|
|
light_ray.D = ao_D;
|
|
light_ray.t = kernel_data.background.ao_distance;
|
|
#ifdef __OBJECT_MOTION__
|
|
light_ray.time = sd.time;
|
|
#endif
|
|
light_ray.dP = sd.dP;
|
|
light_ray.dD = differential3_zero();
|
|
|
|
if(!shadow_blocked(kg, &state, &light_ray, &ao_shadow))
|
|
path_radiance_accum_ao(L, throughput, ao_bsdf, ao_shadow, state.bounce);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#ifdef __EMISSION__
|
|
if(kernel_data.integrator.use_direct_light) {
|
|
/* sample illumination from lights to find path contribution */
|
|
if(sd.flag & SD_BSDF_HAS_EVAL) {
|
|
float light_t = path_rng_1D(kg, rng, sample, num_total_samples, rng_offset + PRNG_LIGHT);
|
|
#ifdef __MULTI_CLOSURE__
|
|
float light_o = 0.0f;
|
|
#else
|
|
float light_o = path_rng_1D(kg, rng, sample, num_total_samples, rng_offset + PRNG_LIGHT_F);
|
|
#endif
|
|
float2 light_uv = path_rng_2D(kg, rng, sample, num_total_samples, rng_offset + PRNG_LIGHT_U);
|
|
float light_u = light_uv.x;
|
|
float light_v = light_uv.y;
|
|
|
|
Ray light_ray;
|
|
BsdfEval L_light;
|
|
bool is_lamp;
|
|
|
|
#ifdef __OBJECT_MOTION__
|
|
light_ray.time = sd.time;
|
|
#endif
|
|
|
|
/* sample random light */
|
|
if(direct_emission(kg, &sd, -1, light_t, light_o, light_u, light_v, &light_ray, &L_light, &is_lamp)) {
|
|
/* trace shadow ray */
|
|
float3 shadow;
|
|
|
|
if(!shadow_blocked(kg, &state, &light_ray, &shadow)) {
|
|
/* accumulate */
|
|
path_radiance_accum_light(L, throughput, &L_light, shadow, 1.0f, state.bounce, is_lamp);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/* no BSDF? we can stop here */
|
|
if(!(sd.flag & SD_BSDF))
|
|
break;
|
|
|
|
/* sample BSDF */
|
|
float bsdf_pdf;
|
|
BsdfEval bsdf_eval;
|
|
float3 bsdf_omega_in;
|
|
differential3 bsdf_domega_in;
|
|
float2 bsdf_uv = path_rng_2D(kg, rng, sample, num_total_samples, rng_offset + PRNG_BSDF_U);
|
|
float bsdf_u = bsdf_uv.x;
|
|
float bsdf_v = bsdf_uv.y;
|
|
int label;
|
|
|
|
label = shader_bsdf_sample(kg, &sd, bsdf_u, bsdf_v, &bsdf_eval,
|
|
&bsdf_omega_in, &bsdf_domega_in, &bsdf_pdf);
|
|
|
|
if(bsdf_pdf == 0.0f || bsdf_eval_is_zero(&bsdf_eval))
|
|
break;
|
|
|
|
/* modify throughput */
|
|
path_radiance_bsdf_bounce(L, &throughput, &bsdf_eval, bsdf_pdf, state.bounce, label);
|
|
|
|
/* set labels */
|
|
if(!(label & LABEL_TRANSPARENT)) {
|
|
ray_pdf = bsdf_pdf;
|
|
#ifdef __LAMP_MIS__
|
|
ray_t = 0.0f;
|
|
#endif
|
|
min_ray_pdf = fminf(bsdf_pdf, min_ray_pdf);
|
|
}
|
|
|
|
/* update path state */
|
|
path_state_next(kg, &state, label);
|
|
|
|
/* setup ray */
|
|
ray.P = ray_offset(sd.P, (label & LABEL_TRANSMIT)? -sd.Ng: sd.Ng);
|
|
ray.D = bsdf_omega_in;
|
|
ray.t = FLT_MAX;
|
|
#ifdef __RAY_DIFFERENTIALS__
|
|
ray.dP = sd.dP;
|
|
ray.dD = bsdf_domega_in;
|
|
#endif
|
|
}
|
|
}
|
|
|
|
__device_noinline void kernel_path_non_progressive_lighting(KernelGlobals *kg, RNG *rng, int sample,
|
|
ShaderData *sd, float3 throughput, float num_samples_adjust,
|
|
float min_ray_pdf, float ray_pdf, PathState state,
|
|
int rng_offset, PathRadiance *L, __global float *buffer)
|
|
{
|
|
int aa_samples = kernel_data.integrator.aa_samples;
|
|
|
|
#ifdef __AO__
|
|
/* ambient occlusion */
|
|
if(kernel_data.integrator.use_ambient_occlusion || (sd->flag & SD_AO)) {
|
|
int num_samples = ceil_to_int(kernel_data.integrator.ao_samples*num_samples_adjust);
|
|
float num_samples_inv = num_samples_adjust/num_samples;
|
|
float ao_factor = kernel_data.background.ao_factor;
|
|
float3 ao_N;
|
|
float3 ao_bsdf = shader_bsdf_ao(kg, sd, ao_factor, &ao_N);
|
|
|
|
for(int j = 0; j < num_samples; j++) {
|
|
/* todo: solve correlation */
|
|
float2 bsdf_uv = path_rng_2D(kg, rng, sample*num_samples + j, aa_samples*num_samples, rng_offset + PRNG_BSDF_U);
|
|
float bsdf_u = bsdf_uv.x;
|
|
float bsdf_v = bsdf_uv.y;
|
|
|
|
float3 ao_D;
|
|
float ao_pdf;
|
|
|
|
sample_cos_hemisphere(ao_N, bsdf_u, bsdf_v, &ao_D, &ao_pdf);
|
|
|
|
if(dot(sd->Ng, ao_D) > 0.0f && ao_pdf != 0.0f) {
|
|
Ray light_ray;
|
|
float3 ao_shadow;
|
|
|
|
light_ray.P = ray_offset(sd->P, sd->Ng);
|
|
light_ray.D = ao_D;
|
|
light_ray.t = kernel_data.background.ao_distance;
|
|
#ifdef __OBJECT_MOTION__
|
|
light_ray.time = sd->time;
|
|
#endif
|
|
light_ray.dP = sd->dP;
|
|
light_ray.dD = differential3_zero();
|
|
|
|
if(!shadow_blocked(kg, &state, &light_ray, &ao_shadow))
|
|
path_radiance_accum_ao(L, throughput*num_samples_inv, ao_bsdf, ao_shadow, state.bounce);
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
|
|
#ifdef __EMISSION__
|
|
/* sample illumination from lights to find path contribution */
|
|
if(sd->flag & SD_BSDF_HAS_EVAL) {
|
|
Ray light_ray;
|
|
BsdfEval L_light;
|
|
bool is_lamp;
|
|
|
|
#ifdef __OBJECT_MOTION__
|
|
light_ray.time = sd->time;
|
|
#endif
|
|
|
|
/* lamp sampling */
|
|
for(int i = 0; i < kernel_data.integrator.num_all_lights; i++) {
|
|
int num_samples = ceil_to_int(num_samples_adjust*light_select_num_samples(kg, i));
|
|
float num_samples_inv = num_samples_adjust/(num_samples*kernel_data.integrator.num_all_lights);
|
|
RNG lamp_rng = cmj_hash(*rng, i);
|
|
|
|
if(kernel_data.integrator.pdf_triangles != 0.0f)
|
|
num_samples_inv *= 0.5f;
|
|
|
|
for(int j = 0; j < num_samples; j++) {
|
|
float2 light_uv = path_rng_2D(kg, &lamp_rng, sample*num_samples + j, aa_samples*num_samples, rng_offset + PRNG_LIGHT_U);
|
|
float light_u = light_uv.x;
|
|
float light_v = light_uv.y;
|
|
|
|
if(direct_emission(kg, sd, i, 0.0f, 0.0f, light_u, light_v, &light_ray, &L_light, &is_lamp)) {
|
|
/* trace shadow ray */
|
|
float3 shadow;
|
|
|
|
if(!shadow_blocked(kg, &state, &light_ray, &shadow)) {
|
|
/* accumulate */
|
|
path_radiance_accum_light(L, throughput*num_samples_inv, &L_light, shadow, num_samples_inv, state.bounce, is_lamp);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* mesh light sampling */
|
|
if(kernel_data.integrator.pdf_triangles != 0.0f) {
|
|
int num_samples = ceil_to_int(num_samples_adjust*kernel_data.integrator.mesh_light_samples);
|
|
float num_samples_inv = num_samples_adjust/num_samples;
|
|
|
|
if(kernel_data.integrator.num_all_lights)
|
|
num_samples_inv *= 0.5f;
|
|
|
|
for(int j = 0; j < num_samples; j++) {
|
|
float light_t = path_rng_1D(kg, rng, sample*num_samples + j, aa_samples*num_samples, rng_offset + PRNG_LIGHT);
|
|
float2 light_uv = path_rng_2D(kg, rng, sample*num_samples + j, aa_samples*num_samples, rng_offset + PRNG_LIGHT_U);
|
|
float light_u = light_uv.x;
|
|
float light_v = light_uv.y;
|
|
|
|
/* only sample triangle lights */
|
|
if(kernel_data.integrator.num_all_lights)
|
|
light_t = 0.5f*light_t;
|
|
|
|
if(direct_emission(kg, sd, -1, light_t, 0.0f, light_u, light_v, &light_ray, &L_light, &is_lamp)) {
|
|
/* trace shadow ray */
|
|
float3 shadow;
|
|
|
|
if(!shadow_blocked(kg, &state, &light_ray, &shadow)) {
|
|
/* accumulate */
|
|
path_radiance_accum_light(L, throughput*num_samples_inv, &L_light, shadow, num_samples_inv, state.bounce, is_lamp);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
for(int i = 0; i< sd->num_closure; i++) {
|
|
const ShaderClosure *sc = &sd->closure[i];
|
|
|
|
if(!CLOSURE_IS_BSDF(sc->type))
|
|
continue;
|
|
/* transparency is not handled here, but in outer loop */
|
|
if(sc->type == CLOSURE_BSDF_TRANSPARENT_ID)
|
|
continue;
|
|
|
|
int num_samples;
|
|
|
|
if(CLOSURE_IS_BSDF_DIFFUSE(sc->type))
|
|
num_samples = kernel_data.integrator.diffuse_samples;
|
|
else if(CLOSURE_IS_BSDF_GLOSSY(sc->type))
|
|
num_samples = kernel_data.integrator.glossy_samples;
|
|
else
|
|
num_samples = kernel_data.integrator.transmission_samples;
|
|
|
|
num_samples = ceil_to_int(num_samples_adjust*num_samples);
|
|
|
|
float num_samples_inv = num_samples_adjust/num_samples;
|
|
RNG bsdf_rng = cmj_hash(*rng, i);
|
|
|
|
for(int j = 0; j < num_samples; j++) {
|
|
/* sample BSDF */
|
|
float bsdf_pdf;
|
|
BsdfEval bsdf_eval;
|
|
float3 bsdf_omega_in;
|
|
differential3 bsdf_domega_in;
|
|
float2 bsdf_uv = path_rng_2D(kg, &bsdf_rng, sample*num_samples + j, aa_samples*num_samples, rng_offset + PRNG_BSDF_U);
|
|
float bsdf_u = bsdf_uv.x;
|
|
float bsdf_v = bsdf_uv.y;
|
|
int label;
|
|
|
|
label = shader_bsdf_sample_closure(kg, sd, sc, bsdf_u, bsdf_v, &bsdf_eval,
|
|
&bsdf_omega_in, &bsdf_domega_in, &bsdf_pdf);
|
|
|
|
if(bsdf_pdf == 0.0f || bsdf_eval_is_zero(&bsdf_eval))
|
|
continue;
|
|
|
|
/* modify throughput */
|
|
float3 tp = throughput;
|
|
path_radiance_bsdf_bounce(L, &tp, &bsdf_eval, bsdf_pdf, state.bounce, label);
|
|
|
|
/* set labels */
|
|
float min_ray_pdf = FLT_MAX;
|
|
|
|
if(!(label & LABEL_TRANSPARENT))
|
|
min_ray_pdf = fminf(bsdf_pdf, min_ray_pdf);
|
|
|
|
/* modify path state */
|
|
PathState ps = state;
|
|
path_state_next(kg, &ps, label);
|
|
|
|
/* setup ray */
|
|
Ray bsdf_ray;
|
|
|
|
bsdf_ray.P = ray_offset(sd->P, (label & LABEL_TRANSMIT)? -sd->Ng: sd->Ng);
|
|
bsdf_ray.D = bsdf_omega_in;
|
|
bsdf_ray.t = FLT_MAX;
|
|
#ifdef __RAY_DIFFERENTIALS__
|
|
bsdf_ray.dP = sd->dP;
|
|
bsdf_ray.dD = bsdf_domega_in;
|
|
#endif
|
|
#ifdef __OBJECT_MOTION__
|
|
bsdf_ray.time = sd->time;
|
|
#endif
|
|
|
|
kernel_path_indirect(kg, rng, sample*num_samples + j, bsdf_ray, buffer,
|
|
tp*num_samples_inv, num_samples, aa_samples*num_samples,
|
|
min_ray_pdf, bsdf_pdf, ps, rng_offset+PRNG_BOUNCE_NUM, L);
|
|
|
|
/* for render passes, sum and reset indirect light pass variables
|
|
* for the next samples */
|
|
path_radiance_sum_indirect(L);
|
|
path_radiance_reset_indirect(L);
|
|
}
|
|
}
|
|
}
|
|
|
|
__device float4 kernel_path_non_progressive(KernelGlobals *kg, RNG *rng, int sample, Ray ray, __global float *buffer)
|
|
{
|
|
/* initialize */
|
|
PathRadiance L;
|
|
float3 throughput = make_float3(1.0f, 1.0f, 1.0f);
|
|
float L_transparent = 0.0f;
|
|
|
|
path_radiance_init(&L, kernel_data.film.use_light_pass);
|
|
|
|
float ray_pdf = 0.0f;
|
|
PathState state;
|
|
int rng_offset = PRNG_BASE_NUM;
|
|
int aa_samples = kernel_data.integrator.aa_samples;
|
|
|
|
path_state_init(&state);
|
|
|
|
for(;; rng_offset += PRNG_BOUNCE_NUM) {
|
|
/* intersect scene */
|
|
Intersection isect;
|
|
uint visibility = path_state_ray_visibility(kg, &state);
|
|
|
|
#ifdef __HAIR__
|
|
float difl = 0.0f, extmax = 0.0f;
|
|
uint lcg_state = 0;
|
|
|
|
if(kernel_data.bvh.have_curves) {
|
|
if((kernel_data.cam.resolution == 1) && (state.flag & PATH_RAY_CAMERA)) {
|
|
float3 pixdiff = ray.dD.dx + ray.dD.dy;
|
|
/*pixdiff = pixdiff - dot(pixdiff, ray.D)*ray.D;*/
|
|
difl = kernel_data.curve_kernel_data.minimum_width * len(pixdiff) * 0.5f;
|
|
}
|
|
|
|
extmax = kernel_data.curve_kernel_data.maximum_width;
|
|
lcg_state = lcg_init(*rng + rng_offset + sample*0x51633e2d);
|
|
}
|
|
|
|
if(!scene_intersect(kg, &ray, visibility, &isect, &lcg_state, difl, extmax)) {
|
|
#else
|
|
if(!scene_intersect(kg, &ray, visibility, &isect)) {
|
|
#endif
|
|
/* eval background shader if nothing hit */
|
|
if(kernel_data.background.transparent) {
|
|
L_transparent += average(throughput);
|
|
|
|
#ifdef __PASSES__
|
|
if(!(kernel_data.film.pass_flag & PASS_BACKGROUND))
|
|
#endif
|
|
break;
|
|
}
|
|
|
|
#ifdef __BACKGROUND__
|
|
/* sample background shader */
|
|
float3 L_background = indirect_background(kg, &ray, state.flag, ray_pdf);
|
|
path_radiance_accum_background(&L, throughput, L_background, state.bounce);
|
|
#endif
|
|
|
|
break;
|
|
}
|
|
|
|
/* setup shading */
|
|
ShaderData sd;
|
|
shader_setup_from_ray(kg, &sd, &isect, &ray);
|
|
shader_eval_surface(kg, &sd, 0.0f, state.flag, SHADER_CONTEXT_MAIN);
|
|
shader_merge_closures(kg, &sd);
|
|
|
|
/* holdout */
|
|
#ifdef __HOLDOUT__
|
|
if((sd.flag & (SD_HOLDOUT|SD_HOLDOUT_MASK))) {
|
|
if(kernel_data.background.transparent) {
|
|
float3 holdout_weight;
|
|
|
|
if(sd.flag & SD_HOLDOUT_MASK)
|
|
holdout_weight = make_float3(1.0f, 1.0f, 1.0f);
|
|
else
|
|
holdout_weight = shader_holdout_eval(kg, &sd);
|
|
|
|
/* any throughput is ok, should all be identical here */
|
|
L_transparent += average(holdout_weight*throughput);
|
|
}
|
|
|
|
if(sd.flag & SD_HOLDOUT_MASK)
|
|
break;
|
|
}
|
|
#endif
|
|
|
|
/* holdout mask objects do not write data passes */
|
|
kernel_write_data_passes(kg, buffer, &L, &sd, sample, state.flag, throughput);
|
|
|
|
#ifdef __EMISSION__
|
|
/* emission */
|
|
if(sd.flag & SD_EMISSION) {
|
|
float3 emission = indirect_primitive_emission(kg, &sd, isect.t, state.flag, ray_pdf);
|
|
path_radiance_accum_emission(&L, throughput, emission, state.bounce);
|
|
}
|
|
#endif
|
|
|
|
/* transparency termination */
|
|
if(state.flag & PATH_RAY_TRANSPARENT) {
|
|
/* path termination. this is a strange place to put the termination, it's
|
|
* mainly due to the mixed in MIS that we use. gives too many unneeded
|
|
* shader evaluations, only need emission if we are going to terminate */
|
|
float probability = path_state_terminate_probability(kg, &state, throughput);
|
|
|
|
if(probability == 0.0f) {
|
|
break;
|
|
}
|
|
else if(probability != 1.0f) {
|
|
float terminate = path_rng_1D(kg, rng, sample, aa_samples, rng_offset + PRNG_TERMINATE);
|
|
|
|
if(terminate >= probability)
|
|
break;
|
|
|
|
throughput /= probability;
|
|
}
|
|
}
|
|
|
|
#ifdef __SUBSURFACE__
|
|
/* bssrdf scatter to a different location on the same object */
|
|
if(sd.flag & SD_BSSRDF) {
|
|
for(int i = 0; i< sd.num_closure; i++) {
|
|
ShaderClosure *sc = &sd.closure[i];
|
|
|
|
if(!CLOSURE_IS_BSSRDF(sc->type))
|
|
continue;
|
|
|
|
/* set up random number generator */
|
|
uint lcg_state = lcg_init(*rng + rng_offset + sample*0x68bc21eb);
|
|
int num_samples = kernel_data.integrator.subsurface_samples;
|
|
float num_samples_inv = 1.0f/num_samples;
|
|
|
|
/* do subsurface scatter step with copy of shader data, this will
|
|
* replace the BSSRDF with a diffuse BSDF closure */
|
|
for(int j = 0; j < num_samples; j++) {
|
|
ShaderData bssrdf_sd = sd;
|
|
subsurface_scatter_step(kg, &bssrdf_sd, state.flag, sc, &lcg_state, true);
|
|
|
|
/* compute lighting with the BSDF closure */
|
|
kernel_path_non_progressive_lighting(kg, rng, sample*num_samples + j,
|
|
&bssrdf_sd, throughput, num_samples_inv,
|
|
ray_pdf, ray_pdf, state, rng_offset, &L, buffer);
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/* lighting */
|
|
kernel_path_non_progressive_lighting(kg, rng, sample, &sd, throughput,
|
|
1.0f, ray_pdf, ray_pdf, state, rng_offset, &L, buffer);
|
|
|
|
/* continue in case of transparency */
|
|
throughput *= shader_bsdf_transparency(kg, &sd);
|
|
|
|
if(is_zero(throughput))
|
|
break;
|
|
|
|
path_state_next(kg, &state, LABEL_TRANSPARENT);
|
|
ray.P = ray_offset(sd.P, -sd.Ng);
|
|
ray.t -= sd.ray_length; /* clipping works through transparent */
|
|
}
|
|
|
|
float3 L_sum = path_radiance_sum(kg, &L);
|
|
|
|
#ifdef __CLAMP_SAMPLE__
|
|
path_radiance_clamp(&L, &L_sum, kernel_data.integrator.sample_clamp);
|
|
#endif
|
|
|
|
kernel_write_light_passes(kg, buffer, &L, sample);
|
|
|
|
return make_float4(L_sum.x, L_sum.y, L_sum.z, 1.0f - L_transparent);
|
|
}
|
|
|
|
#endif
|
|
|
|
__device void kernel_path_trace(KernelGlobals *kg,
|
|
__global float *buffer, __global uint *rng_state,
|
|
int sample, int x, int y, int offset, int stride)
|
|
{
|
|
/* buffer offset */
|
|
int index = offset + x + y*stride;
|
|
int pass_stride = kernel_data.film.pass_stride;
|
|
|
|
rng_state += index;
|
|
buffer += index*pass_stride;
|
|
|
|
/* initialize random numbers */
|
|
RNG rng;
|
|
|
|
float filter_u;
|
|
float filter_v;
|
|
int num_samples = kernel_data.integrator.aa_samples;
|
|
|
|
path_rng_init(kg, rng_state, sample, num_samples, &rng, x, y, &filter_u, &filter_v);
|
|
|
|
/* sample camera ray */
|
|
Ray ray;
|
|
|
|
float lens_u = 0.0f, lens_v = 0.0f;
|
|
|
|
if(kernel_data.cam.aperturesize > 0.0f) {
|
|
float2 lens_uv = path_rng_2D(kg, &rng, sample, num_samples, PRNG_LENS_U);
|
|
lens_u = lens_uv.x;
|
|
lens_v = lens_uv.y;
|
|
}
|
|
|
|
float time = 0.0f;
|
|
|
|
#ifdef __CAMERA_MOTION__
|
|
if(kernel_data.cam.shuttertime != -1.0f)
|
|
time = path_rng_1D(kg, &rng, sample, num_samples, PRNG_TIME);
|
|
#endif
|
|
|
|
camera_sample(kg, x, y, filter_u, filter_v, lens_u, lens_v, time, &ray);
|
|
|
|
/* integrate */
|
|
float4 L;
|
|
|
|
if (ray.t != 0.0f) {
|
|
#ifdef __NON_PROGRESSIVE__
|
|
if(kernel_data.integrator.progressive)
|
|
#endif
|
|
L = kernel_path_progressive(kg, &rng, sample, ray, buffer);
|
|
#ifdef __NON_PROGRESSIVE__
|
|
else
|
|
L = kernel_path_non_progressive(kg, &rng, sample, ray, buffer);
|
|
#endif
|
|
}
|
|
else
|
|
L = make_float4(0.0f, 0.0f, 0.0f, 0.0f);
|
|
|
|
/* accumulate result in output buffer */
|
|
kernel_write_pass_float4(buffer, sample, L);
|
|
|
|
path_rng_end(kg, rng_state, rng);
|
|
}
|
|
|
|
CCL_NAMESPACE_END
|
|
|