[Bf-blender-cvs] [866be3423c6] blender-v2.79a-release: Fix incorrect MIS with principled BSDF and specular roughness 0.

[Brecht Van Lommel]

Commit: 866be3423c61236a90fa071509459b9c659dd9bf
Author: Brecht Van Lommel
Date:   Sat Oct 7 21:43:36 2017 +0200
Branches: blender-v2.79a-release
https://developer.blender.org/rB866be3423c61236a90fa071509459b9c659dd9bf

Fix incorrect MIS with principled BSDF and specular roughness 0.

===================================================================

M	intern/cycles/kernel/closure/bsdf_microfacet.h

===================================================================

diff --git a/intern/cycles/kernel/closure/bsdf_microfacet.h b/intern/cycles/kernel/closure/bsdf_microfacet.h
index 49d396f14b2..18b645e0ecb 100644
--- a/intern/cycles/kernel/closure/bsdf_microfacet.h
+++ b/intern/cycles/kernel/closure/bsdf_microfacet.h
@@ -603,8 +603,7 @@ ccl_device int bsdf_microfacet_ggx_sample(KernelGlobals *kg, const ShaderClosure
 
 						/* if fresnel is used, calculate the color with reflection_color(...) */
 						if(use_fresnel) {
-							*pdf = 1.0f;
-							*eval = reflection_color(bsdf, *omega_in, m);
+							*eval *= reflection_color(bsdf, *omega_in, m);
 						}
 
 						label = LABEL_REFLECT | LABEL_SINGULAR;