Cycles: merge of cycles-x branch, a major update to the renderer

This includes much improved GPU rendering performance, viewport interactivity,
new shadow catcher, revamped sampling settings, subsurface scattering anisotropy,
new GPU volume sampling, improved PMJ sampling pattern, and more.

Some features have also been removed or changed, breaking backwards compatibility.
Including the removal of the OpenCL backend, for which alternatives are under
development.

Release notes and code docs:
https://wiki.blender.org/wiki/Reference/Release_Notes/3.0/Cycles
https://wiki.blender.org/wiki/Source/Render/Cycles

Credits:
* Sergey Sharybin
* Brecht Van Lommel
* Patrick Mours (OptiX backend)
* Christophe Hery (subsurface scattering anisotropy)
* William Leeson (PMJ sampling pattern)
* Alaska (various fixes and tweaks)
* Thomas Dinges (various fixes)

For the full commit history, see the cycles-x branch. This squashes together
all the changes since intermediate changes would often fail building or tests.

Ref T87839, T87837, T87836
Fixes T90734, T89353, T80267, T80267, T77185, T69800

1 files changed, 0 insertions, 360 deletions

diff --git a/intern/cycles/kernel/kernel_path_surface.h b/intern/cycles/kernel/kernel_path_surface.h
deleted file mode 100644
index ba48c0bdfc4..00000000000
--- a/intern/cycles/kernel/kernel_path_surface.h
+++ /dev/null
@@ -1,360 +0,0 @@
-/*
- * 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
-
-#if defined(__BRANCHED_PATH__) || defined(__SUBSURFACE__) || defined(__SHADOW_TRICKS__) || \
-    defined(__BAKING__)
-/* branched path tracing: connect path directly to position on one or more lights and add it to L
- */
-ccl_device_noinline_cpu void kernel_branched_path_surface_connect_light(
-    KernelGlobals *kg,
-    ShaderData *sd,
-    ShaderData *emission_sd,
-    ccl_addr_space PathState *state,
-    float3 throughput,
-    float num_samples_adjust,
-    PathRadiance *L,
-    int sample_all_lights)
-{
-#  ifdef __EMISSION__
-  /* sample illumination from lights to find path contribution */
-  BsdfEval L_light ccl_optional_struct_init;
-
-  int num_lights = 0;
-  if (kernel_data.integrator.use_direct_light) {
-    if (sample_all_lights) {
-      num_lights = kernel_data.integrator.num_all_lights;
-      if (kernel_data.integrator.pdf_triangles != 0.0f) {
-        num_lights += 1;
-      }
-    }
-    else {
-      num_lights = 1;
-    }
-  }
-
-  for (int i = 0; i < num_lights; i++) {
-    /* sample one light at random */
-    int num_samples = 1;
-    int num_all_lights = 1;
-    uint lamp_rng_hash = state->rng_hash;
-    bool double_pdf = false;
-    bool is_mesh_light = false;
-    bool is_lamp = false;
-
-    if (sample_all_lights) {
-      /* lamp sampling */
-      is_lamp = i < kernel_data.integrator.num_all_lights;
-      if (is_lamp) {
-        if (UNLIKELY(light_select_reached_max_bounces(kg, i, state->bounce))) {
-          continue;
-        }
-        num_samples = ceil_to_int(num_samples_adjust * light_select_num_samples(kg, i));
-        num_all_lights = kernel_data.integrator.num_all_lights;
-        lamp_rng_hash = cmj_hash(state->rng_hash, i);
-        double_pdf = kernel_data.integrator.pdf_triangles != 0.0f;
-      }
-      /* mesh light sampling */
-      else {
-        num_samples = ceil_to_int(num_samples_adjust * kernel_data.integrator.mesh_light_samples);
-        double_pdf = kernel_data.integrator.num_all_lights != 0;
-        is_mesh_light = true;
-      }
-    }
-
-    float num_samples_inv = num_samples_adjust / (num_samples * num_all_lights);
-
-    for (int j = 0; j < num_samples; j++) {
-      Ray light_ray ccl_optional_struct_init;
-      light_ray.t = 0.0f; /* reset ray */
-#    ifdef __OBJECT_MOTION__
-      light_ray.time = sd->time;
-#    endif
-      bool has_emission = false;
-
-      if (kernel_data.integrator.use_direct_light && (sd->flag & SD_BSDF_HAS_EVAL)) {
-        float light_u, light_v;
-        path_branched_rng_2D(
-            kg, lamp_rng_hash, state, j, num_samples, PRNG_LIGHT_U, &light_u, &light_v);
-        float terminate = path_branched_rng_light_termination(
-            kg, lamp_rng_hash, state, j, num_samples);
-
-        /* only sample triangle lights */
-        if (is_mesh_light && double_pdf) {
-          light_u = 0.5f * light_u;
-        }
-
-        LightSample ls ccl_optional_struct_init;
-        const int lamp = is_lamp ? i : -1;
-        if (light_sample(kg, lamp, light_u, light_v, sd->time, sd->P, state->bounce, &ls)) {
-          /* The sampling probability returned by lamp_light_sample assumes that all lights were
-           * sampled. However, this code only samples lamps, so if the scene also had mesh lights,
-           * the real probability is twice as high. */
-          if (double_pdf) {
-            ls.pdf *= 2.0f;
-          }
-
-          has_emission = direct_emission(
-              kg, sd, emission_sd, &ls, state, &light_ray, &L_light, &is_lamp, terminate);
-        }
-      }
-
-      /* trace shadow ray */
-      float3 shadow;
-
-      const bool blocked = shadow_blocked(kg, sd, emission_sd, state, &light_ray, &shadow);
-
-      if (has_emission) {
-        if (!blocked) {
-          /* accumulate */
-          path_radiance_accum_light(kg,
-                                    L,
-                                    state,
-                                    throughput * num_samples_inv,
-                                    &L_light,
-                                    shadow,
-                                    num_samples_inv,
-                                    is_lamp);
-        }
-        else {
-          path_radiance_accum_total_light(L, state, throughput * num_samples_inv, &L_light);
-        }
-      }
-    }
-  }
-#  endif
-}
-
-/* branched path tracing: bounce off or through surface to with new direction stored in ray */
-ccl_device bool kernel_branched_path_surface_bounce(KernelGlobals *kg,
-                                                    ShaderData *sd,
-                                                    const ShaderClosure *sc,
-                                                    int sample,
-                                                    int num_samples,
-                                                    ccl_addr_space float3 *throughput,
-                                                    ccl_addr_space PathState *state,
-                                                    PathRadianceState *L_state,
-                                                    ccl_addr_space Ray *ray,
-                                                    float sum_sample_weight)
-{
-  /* sample BSDF */
-  float bsdf_pdf;
-  BsdfEval bsdf_eval ccl_optional_struct_init;
-  float3 bsdf_omega_in ccl_optional_struct_init;
-  differential3 bsdf_domega_in ccl_optional_struct_init;
-  float bsdf_u, bsdf_v;
-  path_branched_rng_2D(
-      kg, state->rng_hash, state, sample, num_samples, PRNG_BSDF_U, &bsdf_u, &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))
-    return false;
-
-  /* modify throughput */
-  path_radiance_bsdf_bounce(kg, L_state, throughput, &bsdf_eval, bsdf_pdf, state->bounce, label);
-
-#  ifdef __DENOISING_FEATURES__
-  state->denoising_feature_weight *= sc->sample_weight / (sum_sample_weight * num_samples);
-#  endif
-
-  /* modify 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 = normalize(bsdf_omega_in);
-  ray->t = FLT_MAX;
-#  ifdef __RAY_DIFFERENTIALS__
-  ray->dP = sd->dP;
-  ray->dD = bsdf_domega_in;
-#  endif
-#  ifdef __OBJECT_MOTION__
-  ray->time = sd->time;
-#  endif
-
-#  ifdef __VOLUME__
-  /* enter/exit volume */
-  if (label & LABEL_TRANSMIT)
-    kernel_volume_stack_enter_exit(kg, sd, state->volume_stack);
-#  endif
-
-  /* branch RNG state */
-  path_state_branch(state, sample, num_samples);
-
-  /* set MIS state */
-  state->min_ray_pdf = fminf(bsdf_pdf, FLT_MAX);
-  state->ray_pdf = bsdf_pdf;
-#  ifdef __LAMP_MIS__
-  state->ray_t = 0.0f;
-#  endif
-
-  return true;
-}
-
-#endif
-
-/* path tracing: connect path directly to position on a light and add it to L */
-ccl_device_inline void kernel_path_surface_connect_light(KernelGlobals *kg,
-                                                         ShaderData *sd,
-                                                         ShaderData *emission_sd,
-                                                         float3 throughput,
-                                                         ccl_addr_space PathState *state,
-                                                         PathRadiance *L)
-{
-  PROFILING_INIT(kg, PROFILING_CONNECT_LIGHT);
-
-#ifdef __EMISSION__
-#  ifdef __SHADOW_TRICKS__
-  int all = (state->flag & PATH_RAY_SHADOW_CATCHER);
-  kernel_branched_path_surface_connect_light(kg, sd, emission_sd, state, throughput, 1.0f, L, all);
-#  else
-  /* sample illumination from lights to find path contribution */
-  Ray light_ray ccl_optional_struct_init;
-  BsdfEval L_light ccl_optional_struct_init;
-  bool is_lamp = false;
-  bool has_emission = false;
-
-  light_ray.t = 0.0f;
-#    ifdef __OBJECT_MOTION__
-  light_ray.time = sd->time;
-#    endif
-
-  if (kernel_data.integrator.use_direct_light && (sd->flag & SD_BSDF_HAS_EVAL)) {
-    float light_u, light_v;
-    path_state_rng_2D(kg, state, PRNG_LIGHT_U, &light_u, &light_v);
-
-    LightSample ls ccl_optional_struct_init;
-    if (light_sample(kg, -1, light_u, light_v, sd->time, sd->P, state->bounce, &ls)) {
-      float terminate = path_state_rng_light_termination(kg, state);
-      has_emission = direct_emission(
-          kg, sd, emission_sd, &ls, state, &light_ray, &L_light, &is_lamp, terminate);
-    }
-  }
-
-  /* trace shadow ray */
-  float3 shadow;
-
-  const bool blocked = shadow_blocked(kg, sd, emission_sd, state, &light_ray, &shadow);
-
-  if (has_emission) {
-    if (!blocked) {
-      /* accumulate */
-      path_radiance_accum_light(kg, L, state, throughput, &L_light, shadow, 1.0f, is_lamp);
-    }
-    else {
-      path_radiance_accum_total_light(L, state, throughput, &L_light);
-    }
-  }
-#  endif
-#endif
-}
-
-/* path tracing: bounce off or through surface to with new direction stored in ray */
-ccl_device bool kernel_path_surface_bounce(KernelGlobals *kg,
-                                           ShaderData *sd,
-                                           ccl_addr_space float3 *throughput,
-                                           ccl_addr_space PathState *state,
-                                           PathRadianceState *L_state,
-                                           ccl_addr_space Ray *ray)
-{
-  PROFILING_INIT(kg, PROFILING_SURFACE_BOUNCE);
-
-  /* no BSDF? we can stop here */
-  if (sd->flag & SD_BSDF) {
-    /* sample BSDF */
-    float bsdf_pdf;
-    BsdfEval bsdf_eval ccl_optional_struct_init;
-    float3 bsdf_omega_in ccl_optional_struct_init;
-    differential3 bsdf_domega_in ccl_optional_struct_init;
-    float bsdf_u, bsdf_v;
-    path_state_rng_2D(kg, state, PRNG_BSDF_U, &bsdf_u, &bsdf_v);
-    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))
-      return false;
-
-    /* modify throughput */
-    path_radiance_bsdf_bounce(kg, L_state, throughput, &bsdf_eval, bsdf_pdf, state->bounce, label);
-
-    /* set labels */
-    if (!(label & LABEL_TRANSPARENT)) {
-      state->ray_pdf = bsdf_pdf;
-#ifdef __LAMP_MIS__
-      state->ray_t = 0.0f;
-#endif
-      state->min_ray_pdf = fminf(bsdf_pdf, state->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 = normalize(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
-
-#ifdef __VOLUME__
-    /* enter/exit volume */
-    if (label & LABEL_TRANSMIT)
-      kernel_volume_stack_enter_exit(kg, sd, state->volume_stack);
-#endif
-    return true;
-  }
-#ifdef __VOLUME__
-  else if (sd->flag & SD_HAS_ONLY_VOLUME) {
-    if (!path_state_volume_next(kg, state)) {
-      return false;
-    }
-
-    if (state->bounce == 0)
-      ray->t -= sd->ray_length; /* clipping works through transparent */
-    else
-      ray->t = FLT_MAX;
-
-    /* setup ray position, direction stays unchanged */
-    ray->P = ray_offset(sd->P, -sd->Ng);
-#  ifdef __RAY_DIFFERENTIALS__
-    ray->dP = sd->dP;
-#  endif
-
-    /* enter/exit volume */
-    kernel_volume_stack_enter_exit(kg, sd, state->volume_stack);
-    return true;
-  }
-#endif
-  else {
-    /* no bsdf or volume? */
-    return false;
-  }
-}
-
-CCL_NAMESPACE_END