Distance Scrambling for for Cycles X - Sobol version

Cycles:Distance Scrambling for Cycles Sobol Sampler

This option implements micro jittering an is based on the INRIA
research paper [[ https://hal.inria.fr/hal-01325702/document | on micro jittering ]]
and work by Lukas Stockner for implementing the scrambling distance.
It works by controlling the correlation between pixels by either using
a user supplied value or an adaptive algorithm to limit the maximum
deviation of the sample values between pixels.

This is a follow up of https://developer.blender.org/D12316

The PMJ version can be found here: https://developer.blender.org/D12511

Reviewed By: leesonw

Differential Revision: https://developer.blender.org/D12318

1 files changed, 15 insertions, 0 deletions

diff --git a/intern/cycles/blender/sync.cpp b/intern/cycles/blender/sync.cpp
index 73d3a4436b5..f6f490077a7 100644
--- a/intern/cycles/blender/sync.cpp
+++ b/intern/cycles/blender/sync.cpp
@@ -352,6 +352,21 @@ void BlenderSync::sync_integrator(BL::ViewLayer &b_view_layer, bool background)
     integrator->set_adaptive_min_samples(get_int(cscene, "adaptive_min_samples"));
   }
 
+  int samples = get_int(cscene, "samples");
+  float scrambling_distance = get_float(cscene, "scrambling_distance");
+  bool adaptive_scrambling_distance = get_boolean(cscene, "adaptive_scrambling_distance");
+  if (adaptive_scrambling_distance) {
+    scrambling_distance *= 4.0f / sqrtf(samples);
+  }
+
+  /* only use scrambling distance in the viewport if user wants to and disable with AS */
+  bool preview_scrambling_distance = get_boolean(cscene, "preview_scrambling_distance");
+  if ((preview && !preview_scrambling_distance) || sampling_pattern != SAMPLING_PATTERN_SOBOL)
+    scrambling_distance = 1.0f;
+
+  VLOG(1) << "Used Scrambling Distance: " << scrambling_distance;
+  integrator->set_scrambling_distance(scrambling_distance);
+
   if (get_boolean(cscene, "use_fast_gi")) {
     if (preview) {
       integrator->set_ao_bounces(get_int(cscene, "ao_bounces"));