blender/intern/cycles/kernel/kernel_path_state.h

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/*
* Copyright 2011-2013 Blender Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License
*/
CCL_NAMESPACE_BEGIN
Cycles: Add support for cameras inside volume Basically the title says it all, volume stack initialization now is aware that camera might be inside of the volume. This gives quite noticeable render time regressions in cases camera is in the volume (didn't measure them yet) because this requires quite a few of ray-casting per camera ray in order to check which objects we're inside. Not quite sure if this might be optimized. But the good thing is that we can do quite a good job on detecting whether camera is outside of any of the volumes and in this case there should be no time penalty at all (apart from some extra checks during the sync state). For now we're only doing rather simple AABB checks between the viewplane and volume objects. This could give some false-positives, but this should be good starting point. Need to mention panoramic cameras here, for them it's only check for whether there are volumes in the scene, which would lead to speed regressions even if the camera is outside of the volumes. Would need to figure out proper check for such cameras. There are still quite a few of TODOs in the code, but the patch is good enough to start playing around with it checking whether there are some obvious mistakes somewhere. Currently the feature is only available in the Experimental feature sey, need to solve some of the TODOs and look into making things faster before considering the feature is ready for the official feature set. This would still likely happen in current release cycle. Reviewers: brecht, juicyfruit, dingto Differential Revision: https://developer.blender.org/D794
2014-09-16 17:49:59 +00:00
ccl_device_inline void path_state_init(KernelGlobals *kg, PathState *state, RNG *rng, int sample, Ray *ray)
{
state->flag = PATH_RAY_CAMERA|PATH_RAY_MIS_SKIP;
state->rng_offset = PRNG_BASE_NUM;
state->sample = sample;
state->num_samples = kernel_data.integrator.aa_samples;
state->bounce = 0;
state->diffuse_bounce = 0;
state->glossy_bounce = 0;
state->transmission_bounce = 0;
state->transparent_bounce = 0;
state->min_ray_pdf = FLT_MAX;
state->ray_pdf = 0.0f;
#ifdef __LAMP_MIS__
state->ray_t = 0.0f;
#endif
#ifdef __VOLUME__
state->volume_bounce = 0;
if(kernel_data.integrator.use_volumes) {
/* initialize volume stack with volume we are inside of */
Cycles: Add support for cameras inside volume Basically the title says it all, volume stack initialization now is aware that camera might be inside of the volume. This gives quite noticeable render time regressions in cases camera is in the volume (didn't measure them yet) because this requires quite a few of ray-casting per camera ray in order to check which objects we're inside. Not quite sure if this might be optimized. But the good thing is that we can do quite a good job on detecting whether camera is outside of any of the volumes and in this case there should be no time penalty at all (apart from some extra checks during the sync state). For now we're only doing rather simple AABB checks between the viewplane and volume objects. This could give some false-positives, but this should be good starting point. Need to mention panoramic cameras here, for them it's only check for whether there are volumes in the scene, which would lead to speed regressions even if the camera is outside of the volumes. Would need to figure out proper check for such cameras. There are still quite a few of TODOs in the code, but the patch is good enough to start playing around with it checking whether there are some obvious mistakes somewhere. Currently the feature is only available in the Experimental feature sey, need to solve some of the TODOs and look into making things faster before considering the feature is ready for the official feature set. This would still likely happen in current release cycle. Reviewers: brecht, juicyfruit, dingto Differential Revision: https://developer.blender.org/D794
2014-09-16 17:49:59 +00:00
kernel_volume_stack_init(kg, ray, state->volume_stack);
/* seed RNG for cases where we can't use stratified samples */
state->rng_congruential = lcg_init(*rng + sample*0x51633e2d);
}
else {
state->volume_stack[0].shader = SHADER_NONE;
}
#endif
}
ccl_device_inline void path_state_next(KernelGlobals *kg, PathState *state, int label)
{
/* ray through transparent keeps same flags from previous ray and is
* not counted as a regular bounce, transparent has separate max */
if(label & LABEL_TRANSPARENT) {
state->flag |= PATH_RAY_TRANSPARENT;
state->transparent_bounce++;
/* don't increase random number generator offset here, to avoid some
* unwanted patterns, see path_state_rng_1D_for_decision */
if(!kernel_data.integrator.transparent_shadows)
state->flag |= PATH_RAY_MIS_SKIP;
return;
}
state->bounce++;
#ifdef __VOLUME__
if(label & LABEL_VOLUME_SCATTER) {
/* volume scatter */
state->flag |= PATH_RAY_VOLUME_SCATTER;
state->flag &= ~(PATH_RAY_REFLECT|PATH_RAY_TRANSMIT|PATH_RAY_CAMERA|PATH_RAY_TRANSPARENT|PATH_RAY_DIFFUSE|PATH_RAY_GLOSSY|PATH_RAY_SINGULAR|PATH_RAY_MIS_SKIP);
state->volume_bounce++;
}
else
#endif
{
/* surface reflection/transmission */
if(label & LABEL_REFLECT) {
state->flag |= PATH_RAY_REFLECT;
state->flag &= ~(PATH_RAY_TRANSMIT|PATH_RAY_VOLUME_SCATTER|PATH_RAY_CAMERA|PATH_RAY_TRANSPARENT);
if(label & LABEL_DIFFUSE)
state->diffuse_bounce++;
else
state->glossy_bounce++;
}
else {
kernel_assert(label & LABEL_TRANSMIT);
state->flag |= PATH_RAY_TRANSMIT;
state->flag &= ~(PATH_RAY_REFLECT|PATH_RAY_VOLUME_SCATTER|PATH_RAY_CAMERA|PATH_RAY_TRANSPARENT);
state->transmission_bounce++;
}
/* diffuse/glossy/singular */
if(label & LABEL_DIFFUSE) {
state->flag |= PATH_RAY_DIFFUSE|PATH_RAY_DIFFUSE_ANCESTOR;
state->flag &= ~(PATH_RAY_GLOSSY|PATH_RAY_SINGULAR|PATH_RAY_MIS_SKIP);
}
else if(label & LABEL_GLOSSY) {
state->flag |= PATH_RAY_GLOSSY|PATH_RAY_GLOSSY_ANCESTOR;
state->flag &= ~(PATH_RAY_DIFFUSE|PATH_RAY_SINGULAR|PATH_RAY_MIS_SKIP);
}
else {
kernel_assert(label & LABEL_SINGULAR);
state->flag |= PATH_RAY_GLOSSY|PATH_RAY_SINGULAR|PATH_RAY_MIS_SKIP;
state->flag &= ~PATH_RAY_DIFFUSE;
}
}
/* random number generator next bounce */
state->rng_offset += PRNG_BOUNCE_NUM;
}
ccl_device_inline uint path_state_ray_visibility(KernelGlobals *kg, PathState *state)
{
uint flag = state->flag & PATH_RAY_ALL_VISIBILITY;
/* for visibility, diffuse/glossy are for reflection only */
if(flag & PATH_RAY_TRANSMIT)
flag &= ~(PATH_RAY_DIFFUSE|PATH_RAY_GLOSSY);
/* todo: this is not supported as its own ray visibility yet */
if(state->flag & PATH_RAY_VOLUME_SCATTER)
flag |= PATH_RAY_DIFFUSE;
/* for camera visibility, use render layer flags */
if(flag & PATH_RAY_CAMERA)
flag |= kernel_data.integrator.layer_flag;
return flag;
}
ccl_device_inline float path_state_terminate_probability(KernelGlobals *kg, PathState *state, const float3 throughput)
{
if(state->flag & PATH_RAY_TRANSPARENT) {
/* transparent rays treated separately */
if(state->transparent_bounce >= kernel_data.integrator.transparent_max_bounce)
return 0.0f;
else if(state->transparent_bounce <= kernel_data.integrator.transparent_min_bounce)
return 1.0f;
}
else {
/* other rays */
if((state->bounce >= kernel_data.integrator.max_bounce) ||
(state->diffuse_bounce >= kernel_data.integrator.max_diffuse_bounce) ||
(state->glossy_bounce >= kernel_data.integrator.max_glossy_bounce) ||
#ifdef __VOLUME__
(state->volume_bounce >= kernel_data.integrator.max_volume_bounce) ||
#endif
(state->transmission_bounce >= kernel_data.integrator.max_transmission_bounce))
{
return 0.0f;
}
else if(state->bounce <= kernel_data.integrator.min_bounce) {
return 1.0f;
}
}
/* probalistic termination */
return average(throughput); /* todo: try using max here */
}
CCL_NAMESPACE_END