Cycles: initial subsurface multiple scattering support. It's not working as

well as I would like, but it works, just add a subsurface scattering node and
you can use it like any other BSDF.

It is using fully raytraced sampling compatible with progressive rendering
and other more advanced rendering algorithms we might used in the future, and
it uses no extra memory so it's suitable for complex scenes.

Disadvantage is that it can be quite noisy and slow. Two limitations that will
be solved are that it does not work with bump mapping yet, and that the falloff
function used is a simple cubic function, it's not using the real BSSRDF
falloff function yet.

The node has a color input, along with a scattering radius for each RGB color
channel along with an overall scale factor for the radii.

There is also no GPU support yet, will test if I can get that working later.

Node Documentation:
http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes/Shaders#BSSRDF

Implementation notes:
http://wiki.blender.org/index.php/Dev:2.6/Source/Render/Cycles/Subsurface_Scattering

4 files changed, 12 insertions, 1 deletions

diff --git a/intern/cycles/blender/addon/properties.py b/intern/cycles/blender/addon/properties.py
index 039fd39fc7d..ac0a1d7bdb7 100644
--- a/intern/cycles/blender/addon/properties.py
+++ b/intern/cycles/blender/addon/properties.py
@@ -205,6 +205,13 @@ class CyclesRenderSettings(bpy.types.PropertyGroup):
                 default=1,
                 )
 
+        cls.subsurface_samples = IntProperty(
+                name="Subsurface Samples",
+                description="Number of subsurface scattering samples to render for each AA sample",
+                min=1, max=10000,
+                default=1,
+                )
+
         cls.no_caustics = BoolProperty(
                 name="No Caustics",
                 description="Leave out caustics, resulting in a darker image with less noise",
diff --git a/intern/cycles/blender/addon/ui.py b/intern/cycles/blender/addon/ui.py
index 4c3061e13a9..6a9b242c32f 100644
--- a/intern/cycles/blender/addon/ui.py
+++ b/intern/cycles/blender/addon/ui.py
@@ -83,6 +83,7 @@ class CyclesRender_PT_sampling(CyclesButtonsPanel, Panel):
             sub.prop(cscene, "transmission_samples", text="Transmission")
             sub.prop(cscene, "ao_samples", text="AO")
             sub.prop(cscene, "mesh_light_samples", text="Mesh Light")
+            sub.prop(cscene, "subsurface_samples", text="Subsurface")
 
 
 class CyclesRender_PT_light_paths(CyclesButtonsPanel, Panel):
diff --git a/intern/cycles/blender/blender_shader.cpp b/intern/cycles/blender/blender_shader.cpp
index b451764c347..7749f164b90 100644
--- a/intern/cycles/blender/blender_shader.cpp
+++ b/intern/cycles/blender/blender_shader.cpp
@@ -252,7 +252,6 @@ static ShaderNode *add_node(Scene *scene, BL::BlendData b_data, BL::Scene b_scen
 	else if (b_node.is_a(&RNA_ShaderNodeNormal)) {
 		BL::Node::outputs_iterator out_it;
 		b_node.outputs.begin(out_it);
-		BL::NodeSocket vec_sock(*out_it);
 		
 		NormalNode *norm = new NormalNode();
 		norm->direction = get_node_output_vector(b_node, "Normal");
@@ -302,6 +301,9 @@ static ShaderNode *add_node(Scene *scene, BL::BlendData b_data, BL::Scene b_scen
 	else if (b_node.is_a(&RNA_ShaderNodeBsdfDiffuse)) {
 		node = new DiffuseBsdfNode();
 	}
+	else if (b_node.is_a(&RNA_ShaderNodeSubsurfaceScattering)) {
+		node = new SubsurfaceScatteringNode();
+	}
 	else if (b_node.is_a(&RNA_ShaderNodeBsdfGlossy)) {
 		BL::ShaderNodeBsdfGlossy b_glossy_node(b_node);
 		GlossyBsdfNode *glossy = new GlossyBsdfNode();
diff --git a/intern/cycles/blender/blender_sync.cpp b/intern/cycles/blender/blender_sync.cpp
index 66401d80a2e..721eaeefc08 100644
--- a/intern/cycles/blender/blender_sync.cpp
+++ b/intern/cycles/blender/blender_sync.cpp
@@ -196,6 +196,7 @@ void BlenderSync::sync_integrator()
 	integrator->transmission_samples = get_int(cscene, "transmission_samples");
 	integrator->ao_samples = get_int(cscene, "ao_samples");
 	integrator->mesh_light_samples = get_int(cscene, "mesh_light_samples");
+	integrator->subsurface_samples = get_int(cscene, "subsurface_samples");
 	integrator->progressive = get_boolean(cscene, "progressive");
 
 	if(integrator->modified(previntegrator))