Cycles: light_tree_pdf() now accounts for splitting

For the MIS calculations we need to be able to calculate the
probability to sample a light using the light tree. This
did not account for splitting so if splitting was used the
probability would be wrong. This has now been fixed.

Also, if we are in PATH mode then the splitting threshold is
set to zero.

1 files changed, 6 insertions, 1 deletions

diff --git a/intern/cycles/blender/blender_sync.cpp b/intern/cycles/blender/blender_sync.cpp
index bb67099a0c2..73ddfccd91b 100644
--- a/intern/cycles/blender/blender_sync.cpp
+++ b/intern/cycles/blender/blender_sync.cpp
@@ -282,7 +282,12 @@ void BlenderSync::sync_integrator()
 	                                                  Integrator::PATH);
 
 	integrator->use_light_tree = get_boolean(cscene, "use_light_tree");
-	integrator->splitting_threshold = get_float(cscene, "splitting_threshold");
+	if(get_enum(cscene, "progressive") == 0) {
+		integrator->splitting_threshold = get_float(cscene, "splitting_threshold");
+	}
+	else { // Not using branched path tracing
+		integrator->splitting_threshold = 0.0f;
+	}
 	integrator->sample_all_lights_direct = get_boolean(cscene, "sample_all_lights_direct");
 	integrator->sample_all_lights_indirect = get_boolean(cscene, "sample_all_lights_indirect");
 	integrator->light_sampling_threshold = get_float(cscene, "light_sampling_threshold");