forked from bartvdbraak/blender
27d647dcf8
* Tangent: generate a tangent direction for anisotropic shading. Can be either radial around X/Y/Z axis, or from a UV map. The default tangent for the anisotropic BSDF and geometry node is now always radial Z, for UV tangent use this node now. http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes/More#Tangent * Normal Map: generate a perturbed normal from an RGB normal map image. This is usually chained with an Image Texture node in the color input, to specify the normal map image. For tangent space normal maps, the UV coordinates for the image must match, and the image texture should be set to Non-Color mode to give correct results. http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes/More#Normal_Map * Refraction BSDF: for best results this node should be considered as a building block and not be used on its own, but rather mixed with a glossy node using a fresnel type factor. Otherwise it will give quite dark results at the edges for glossy refraction. http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes/Shaders#Refraction * Ambient Occlusion: controls the amount of AO a surface receives, rather than having just a global factor in the world. Note that this outputs a shader and not a color, that's for another time. http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes/Shaders#Ambient_Occlusion
963 lines
27 KiB
C
963 lines
27 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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#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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#ifdef __QBVH__
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#include "kernel_qbvh.h"
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#else
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#include "kernel_bvh.h"
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#endif
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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_random.h"
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#include "kernel_passes.h"
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CCL_NAMESPACE_BEGIN
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typedef struct PathState {
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uint 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);
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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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bool result = scene_intersect(kg, ray, PATH_RAY_SHADOW_OPAQUE, &isect);
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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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if(!scene_intersect(kg, ray, PATH_RAY_SHADOW_TRANSPARENT, &isect)) {
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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);
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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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shader_release(kg, &sd);
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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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PathState state;
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int rng_offset = PRNG_BASE_NUM;
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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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if(!scene_intersect(kg, &ray, visibility, &isect)) {
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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(kg, rng, sample, rng_offset + PRNG_BSDF);
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shader_eval_surface(kg, &sd, rbsdf, state.flag);
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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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/* 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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shader_release(kg, &sd);
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break;
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}
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}
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#endif
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#ifdef __EMISSION__
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/* emission */
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if(sd.flag & SD_EMISSION) {
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float3 emission = indirect_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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float terminate = path_rng(kg, rng, sample, rng_offset + PRNG_TERMINATE);
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if(terminate >= probability) {
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shader_release(kg, &sd);
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break;
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}
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throughput /= probability;
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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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float bsdf_u = path_rng(kg, rng, sample, rng_offset + PRNG_BSDF_U);
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float bsdf_v = path_rng(kg, rng, sample, rng_offset + PRNG_BSDF_V);
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float3 ao_D;
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float ao_pdf;
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sample_cos_hemisphere(sd.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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if(!shadow_blocked(kg, &state, &light_ray, &ao_shadow)) {
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float3 ao_bsdf = shader_bsdf_diffuse(kg, &sd)*kernel_data.background.ao_factor;
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ao_bsdf += shader_bsdf_ao(kg, &sd);
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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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}
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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(kg, rng, sample, rng_offset + PRNG_LIGHT);
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float light_o = path_rng(kg, rng, sample, rng_offset + PRNG_LIGHT_F);
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float light_u = path_rng(kg, rng, sample, rng_offset + PRNG_LIGHT_U);
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float light_v = path_rng(kg, rng, sample, rng_offset + PRNG_LIGHT_V);
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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, 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 */
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if(!(sd.flag & SD_BSDF)) {
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shader_release(kg, &sd);
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break;
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}
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/* sample BSDF */
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float bsdf_pdf;
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BsdfEval bsdf_eval;
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float3 bsdf_omega_in;
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differential3 bsdf_domega_in;
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float bsdf_u = path_rng(kg, rng, sample, rng_offset + PRNG_BSDF_U);
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float bsdf_v = path_rng(kg, rng, sample, rng_offset + PRNG_BSDF_V);
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int label;
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label = shader_bsdf_sample(kg, &sd, bsdf_u, bsdf_v, &bsdf_eval,
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&bsdf_omega_in, &bsdf_domega_in, &bsdf_pdf);
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shader_release(kg, &sd);
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if(bsdf_pdf == 0.0f || bsdf_eval_is_zero(&bsdf_eval))
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break;
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/* modify throughput */
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path_radiance_bsdf_bounce(&L, &throughput, &bsdf_eval, bsdf_pdf, state.bounce, label);
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/* set labels */
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if(!(label & LABEL_TRANSPARENT)) {
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ray_pdf = bsdf_pdf;
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min_ray_pdf = fminf(bsdf_pdf, min_ray_pdf);
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}
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/* update path state */
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path_state_next(kg, &state, label);
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/* setup ray */
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ray.P = ray_offset(sd.P, (label & LABEL_TRANSMIT)? -sd.Ng: sd.Ng);
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ray.D = bsdf_omega_in;
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ray.t = FLT_MAX;
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#ifdef __RAY_DIFFERENTIALS__
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ray.dP = sd.dP;
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ray.dD = bsdf_domega_in;
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#endif
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}
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float3 L_sum = path_radiance_sum(kg, &L);
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#ifdef __CLAMP_SAMPLE__
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path_radiance_clamp(&L, &L_sum, kernel_data.integrator.sample_clamp);
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#endif
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kernel_write_light_passes(kg, buffer, &L, sample);
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return make_float4(L_sum.x, L_sum.y, L_sum.z, 1.0f - L_transparent);
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}
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#ifdef __NON_PROGRESSIVE__
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__device void kernel_path_indirect(KernelGlobals *kg, RNG *rng, int sample, Ray ray, __global float *buffer,
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float3 throughput, float min_ray_pdf, float ray_pdf, PathState state, int rng_offset, PathRadiance *L)
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{
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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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if(!scene_intersect(kg, &ray, visibility, &isect)) {
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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);
|
|
#endif
|
|
|
|
break;
|
|
}
|
|
|
|
/* setup shading */
|
|
ShaderData sd;
|
|
shader_setup_from_ray(kg, &sd, &isect, &ray);
|
|
float rbsdf = path_rng(kg, rng, sample, rng_offset + PRNG_BSDF);
|
|
shader_eval_surface(kg, &sd, rbsdf, state.flag);
|
|
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_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);
|
|
float terminate = path_rng(kg, rng, sample, rng_offset + PRNG_TERMINATE);
|
|
|
|
if(terminate >= probability) {
|
|
shader_release(kg, &sd);
|
|
break;
|
|
}
|
|
|
|
throughput /= probability;
|
|
|
|
#ifdef __AO__
|
|
/* ambient occlusion */
|
|
if(kernel_data.integrator.use_ambient_occlusion || (sd.flag & SD_AO)) {
|
|
/* todo: solve correlation */
|
|
float bsdf_u = path_rng(kg, rng, sample, rng_offset + PRNG_BSDF_U);
|
|
float bsdf_v = path_rng(kg, rng, sample, rng_offset + PRNG_BSDF_V);
|
|
|
|
float3 ao_D;
|
|
float ao_pdf;
|
|
|
|
sample_cos_hemisphere(sd.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
|
|
|
|
if(!shadow_blocked(kg, &state, &light_ray, &ao_shadow)) {
|
|
float3 ao_bsdf = shader_bsdf_diffuse(kg, &sd)*kernel_data.background.ao_factor;
|
|
ao_bsdf += shader_bsdf_ao(kg, &sd);
|
|
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(kg, rng, sample, rng_offset + PRNG_LIGHT);
|
|
float light_o = path_rng(kg, rng, sample, rng_offset + PRNG_LIGHT_F);
|
|
float light_u = path_rng(kg, rng, sample, rng_offset + PRNG_LIGHT_U);
|
|
float light_v = path_rng(kg, rng, sample, rng_offset + PRNG_LIGHT_V);
|
|
|
|
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, state.bounce, is_lamp);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/* no BSDF? we can stop here */
|
|
if(!(sd.flag & SD_BSDF)) {
|
|
shader_release(kg, &sd);
|
|
break;
|
|
}
|
|
|
|
/* sample BSDF */
|
|
float bsdf_pdf;
|
|
BsdfEval bsdf_eval;
|
|
float3 bsdf_omega_in;
|
|
differential3 bsdf_domega_in;
|
|
float bsdf_u = path_rng(kg, rng, sample, rng_offset + PRNG_BSDF_U);
|
|
float bsdf_v = path_rng(kg, rng, sample, rng_offset + PRNG_BSDF_V);
|
|
int label;
|
|
|
|
label = shader_bsdf_sample(kg, &sd, bsdf_u, bsdf_v, &bsdf_eval,
|
|
&bsdf_omega_in, &bsdf_domega_in, &bsdf_pdf);
|
|
|
|
shader_release(kg, &sd);
|
|
|
|
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;
|
|
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 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;
|
|
|
|
path_state_init(&state);
|
|
|
|
for(;; rng_offset += PRNG_BOUNCE_NUM) {
|
|
/* intersect scene */
|
|
Intersection isect;
|
|
uint visibility = path_state_ray_visibility(kg, &state);
|
|
|
|
if(!scene_intersect(kg, &ray, visibility, &isect)) {
|
|
/* 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);
|
|
float rbsdf = path_rng(kg, rng, sample, rng_offset + PRNG_BSDF);
|
|
shader_eval_surface(kg, &sd, rbsdf, state.flag);
|
|
shader_merge_closures(kg, &sd);
|
|
|
|
kernel_write_data_passes(kg, buffer, &L, &sd, sample, state.flag, throughput);
|
|
|
|
/* 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) {
|
|
shader_release(kg, &sd);
|
|
break;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#ifdef __EMISSION__
|
|
/* emission */
|
|
if(sd.flag & SD_EMISSION) {
|
|
float3 emission = indirect_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);
|
|
float terminate = path_rng(kg, rng, sample, rng_offset + PRNG_TERMINATE);
|
|
|
|
if(terminate >= probability) {
|
|
shader_release(kg, &sd);
|
|
break;
|
|
}
|
|
|
|
throughput /= probability;
|
|
}
|
|
|
|
#ifdef __AO__
|
|
/* ambient occlusion */
|
|
if(kernel_data.integrator.use_ambient_occlusion || (sd.flag & SD_AO)) {
|
|
int num_samples = kernel_data.integrator.ao_samples;
|
|
float num_samples_inv = 1.0f/num_samples;
|
|
float ao_factor = kernel_data.background.ao_factor;
|
|
|
|
for(int j = 0; j < num_samples; j++) {
|
|
/* todo: solve correlation */
|
|
float bsdf_u = path_rng(kg, rng, sample*num_samples + j, rng_offset + PRNG_BSDF_U);
|
|
float bsdf_v = path_rng(kg, rng, sample*num_samples + j, rng_offset + PRNG_BSDF_V);
|
|
|
|
float3 ao_D;
|
|
float ao_pdf;
|
|
|
|
sample_cos_hemisphere(sd.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
|
|
|
|
if(!shadow_blocked(kg, &state, &light_ray, &ao_shadow)) {
|
|
float3 ao_bsdf = shader_bsdf_diffuse(kg, &sd)*ao_factor;
|
|
ao_bsdf += shader_bsdf_ao(kg, &sd);
|
|
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 = light_select_num_samples(kg, i);
|
|
float num_samples_inv = 1.0f/(num_samples*kernel_data.integrator.num_all_lights);
|
|
|
|
if(kernel_data.integrator.pdf_triangles != 0.0f)
|
|
num_samples_inv *= 0.5f;
|
|
|
|
for(int j = 0; j < num_samples; j++) {
|
|
float light_u = path_rng(kg, rng, sample*num_samples + j, rng_offset + PRNG_LIGHT_U);
|
|
float light_v = path_rng(kg, rng, sample*num_samples + j, rng_offset + PRNG_LIGHT_V);
|
|
|
|
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, state.bounce, is_lamp);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* mesh light sampling */
|
|
if(kernel_data.integrator.pdf_triangles != 0.0f) {
|
|
int num_samples = kernel_data.integrator.mesh_light_samples;
|
|
float num_samples_inv = 1.0f/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(kg, rng, sample*num_samples + j, rng_offset + PRNG_LIGHT);
|
|
float light_u = path_rng(kg, rng, sample*num_samples + j, rng_offset + PRNG_LIGHT_U);
|
|
float light_v = path_rng(kg, rng, sample*num_samples + j, rng_offset + PRNG_LIGHT_V);
|
|
|
|
/* 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, 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;
|
|
|
|
float num_samples_inv = 1.0f/num_samples;
|
|
|
|
for(int j = 0; j < num_samples; j++) {
|
|
/* sample BSDF */
|
|
float bsdf_pdf;
|
|
BsdfEval bsdf_eval;
|
|
float3 bsdf_omega_in;
|
|
differential3 bsdf_domega_in;
|
|
float bsdf_u = path_rng(kg, rng, sample*num_samples + j, rng_offset + PRNG_BSDF_U);
|
|
float bsdf_v = path_rng(kg, rng, sample*num_samples + j, rng_offset + PRNG_BSDF_V);
|
|
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, bsdf_ray, buffer,
|
|
tp*num_samples_inv, min_ray_pdf, bsdf_pdf, ps, rng_offset+PRNG_BOUNCE_NUM, &L);
|
|
}
|
|
}
|
|
|
|
/* continue in case of transparency */
|
|
throughput *= shader_bsdf_transparency(kg, &sd);
|
|
shader_release(kg, &sd);
|
|
|
|
if(is_zero(throughput))
|
|
break;
|
|
|
|
path_state_next(kg, &state, LABEL_TRANSPARENT);
|
|
ray.P = ray_offset(sd.P, -sd.Ng);
|
|
}
|
|
|
|
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;
|
|
|
|
path_rng_init(kg, rng_state, sample, &rng, x, y, &filter_u, &filter_v);
|
|
|
|
/* sample camera ray */
|
|
Ray ray;
|
|
|
|
float lens_u = path_rng(kg, &rng, sample, PRNG_LENS_U);
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float lens_v = path_rng(kg, &rng, sample, PRNG_LENS_V);
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|
|
|
#ifdef __CAMERA_MOTION__
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float time = path_rng(kg, &rng, sample, PRNG_TIME);
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#else
|
|
float time = 0.0f;
|
|
#endif
|
|
|
|
camera_sample(kg, x, y, filter_u, filter_v, lens_u, lens_v, time, &ray);
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|
|
|
/* 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.f, 0.f, 0.f, 0.f);
|
|
|
|
/* accumulate result in output buffer */
|
|
kernel_write_pass_float4(buffer, sample, L);
|
|
|
|
path_rng_end(kg, rng_state, rng);
|
|
}
|
|
|
|
CCL_NAMESPACE_END
|
|
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