Cycles:

* Fix #29257: nan-pixels with zero roughness for glass/glossy.
* Fix #29239: crash with border rendering, this is not working yet, but should
  no longer crash now.
* Show object name in 3d view rendered draw type.
* Attempt to improve Sample as Light option description.

3 files changed, 10 insertions, 5 deletions

diff --git a/intern/cycles/blender/addon/engine.py b/intern/cycles/blender/addon/engine.py
index 097909ca058..d0f0d395810 100644
--- a/intern/cycles/blender/addon/engine.py
+++ b/intern/cycles/blender/addon/engine.py
@@ -50,11 +50,16 @@ def free(engine):
 
 def render(engine):
     import bcycles
-    bcycles.render(engine.session)
+    if "session" in dir(engine):
+        bcycles.render(engine.session)
 
 def update(engine, data, scene):
     import bcycles
-    bcycles.sync(engine.session)
+    if scene.render.use_border:
+        engine.report({'ERROR'}, "Border rendering not supported yet")
+        free(engine)
+    else:
+        bcycles.sync(engine.session)
 
 def draw(engine, region, v3d, rv3d):
     import bcycles
diff --git a/intern/cycles/blender/addon/properties.py b/intern/cycles/blender/addon/properties.py
index cd3ded2200d..bcd3f7d1eac 100644
--- a/intern/cycles/blender/addon/properties.py
+++ b/intern/cycles/blender/addon/properties.py
@@ -121,7 +121,7 @@ class CyclesMaterialSettings(bpy.types.PropertyGroup):
     @classmethod
     def register(cls):
         bpy.types.Material.cycles = PointerProperty(type=cls, name="Cycles Material Settings", description="Cycles material settings")
-        cls.sample_as_light = BoolProperty(name="Sample as Light", description="Use direct light sampling, to reduce noise for small or strong emitting materials", default=True)
+        cls.sample_as_light = BoolProperty(name="Sample as Lamp", description="Use direct light sampling for this material, disabling may reduce overall noise for large objects that emit little light compared to other light sources", default=True)
         cls.homogeneous_volume = BoolProperty(name="Homogeneous Volume", description="When using volume rendering, assume volume has the same density everywhere, for faster rendering", default=False)
 
     @classmethod
diff --git a/intern/cycles/kernel/svm/bsdf_microfacet.h b/intern/cycles/kernel/svm/bsdf_microfacet.h
index 3acd3ba4c85..077b642c3c1 100644
--- a/intern/cycles/kernel/svm/bsdf_microfacet.h
+++ b/intern/cycles/kernel/svm/bsdf_microfacet.h
@@ -45,7 +45,7 @@ typedef struct BsdfMicrofacetGGXClosure {
 
 __device void bsdf_microfacet_ggx_setup(ShaderData *sd, ShaderClosure *sc, float ag, float eta, bool refractive)
 {
-	float m_ag = clamp(ag, 1e-5f, 1.0f);
+	float m_ag = clamp(ag, 1e-4f, 1.0f);
 	float m_eta = eta;
 
 	sc->data0 = m_ag;
@@ -270,7 +270,7 @@ typedef struct BsdfMicrofacetBeckmannClosure {
 
 __device void bsdf_microfacet_beckmann_setup(ShaderData *sd, ShaderClosure *sc, float ab, float eta, bool refractive)
 {
-	float m_ab = clamp(ab, 1e-5f, 1.0f);
+	float m_ab = clamp(ab, 1e-4f, 1.0f);
 	float m_eta = eta;
 
 	sc->data0 = m_ab;