Merge branch 'master' into blender2.8

5 files changed, 33 insertions, 5 deletions

diff --git a/source/blender/editors/space_node/drawnode.c b/source/blender/editors/space_node/drawnode.c
index ead0e848716..27c4eb2fa3c 100644
--- a/source/blender/editors/space_node/drawnode.c
+++ b/source/blender/editors/space_node/drawnode.c
@@ -1032,6 +1032,12 @@ static void node_shader_buts_glossy(uiLayout *layout, bContext *UNUSED(C), Point
 	uiItemR(layout, ptr, "distribution", 0, "", ICON_NONE);
 }
 
+static void node_shader_buts_principled(uiLayout *layout, bContext *UNUSED(C), PointerRNA *ptr)
+{
+	uiItemR(layout, ptr, "distribution", 0, "", ICON_NONE);
+	uiItemR(layout, ptr, "subsurface_method", 0, "", ICON_NONE);
+}
+
 static void node_shader_buts_anisotropic(uiLayout *layout, bContext *UNUSED(C), PointerRNA *ptr)
 {
 	uiItemR(layout, ptr, "distribution", 0, "", ICON_NONE);
@@ -1204,9 +1210,11 @@ static void node_shader_set_butfunc(bNodeType *ntype)
 		case SH_NODE_BSDF_GLOSSY:
 		case SH_NODE_BSDF_GLASS:
 		case SH_NODE_BSDF_REFRACTION:
-		case SH_NODE_BSDF_PRINCIPLED:
 			ntype->draw_buttons = node_shader_buts_glossy;
 			break;
+		case SH_NODE_BSDF_PRINCIPLED:
+			ntype->draw_buttons = node_shader_buts_principled;
+			break;
 		case SH_NODE_BSDF_ANISOTROPIC:
 			ntype->draw_buttons = node_shader_buts_anisotropic;
 			break;
diff --git a/source/blender/gpu/intern/gpu_material.c b/source/blender/gpu/intern/gpu_material.c
index 2e6c1cbf9df..4efb8ca07b2 100644
--- a/source/blender/gpu/intern/gpu_material.c
+++ b/source/blender/gpu/intern/gpu_material.c
@@ -557,7 +557,9 @@ static float eval_profile(float r, short falloff_type, float sharpness, float pa
 {
 	r = fabsf(r);
 
-	if (falloff_type == SHD_SUBSURFACE_BURLEY) {
+	if (falloff_type == SHD_SUBSURFACE_BURLEY ||
+	    falloff_type == SHD_SUBSURFACE_RANDOM_WALK)
+	{
 		return burley_profile(r, param) / BURLEY_TRUNCATE_CDF;
 	}
 	else if (falloff_type == SHD_SUBSURFACE_CUBIC) {
@@ -598,7 +600,9 @@ static void compute_sss_kernel(
 	/* Christensen-Burley fitting */
 	float l[3], d[3];
 
-	if (falloff_type == SHD_SUBSURFACE_BURLEY) {
+	if (falloff_type == SHD_SUBSURFACE_BURLEY ||
+	    falloff_type == SHD_SUBSURFACE_RANDOM_WALK)
+	{
 		mul_v3_v3fl(l, rad, 0.25f * M_1_PI);
 		const float A = 1.0f;
 		const float s = 1.9f - A + 3.5f * (A - 0.8f) * (A - 0.8f);
diff --git a/source/blender/makesdna/DNA_node_types.h b/source/blender/makesdna/DNA_node_types.h
index bddbf63d8b1..63eecebf44a 100644
--- a/source/blender/makesdna/DNA_node_types.h
+++ b/source/blender/makesdna/DNA_node_types.h
@@ -1077,6 +1077,7 @@ enum {
 	SHD_SUBSURFACE_CUBIC			= 1,
 	SHD_SUBSURFACE_GAUSSIAN			= 2,
 	SHD_SUBSURFACE_BURLEY			= 3,
+	SHD_SUBSURFACE_RANDOM_WALK		= 4,
 };
 
 /* blur node */
diff --git a/source/blender/makesrna/intern/rna_nodetree.c b/source/blender/makesrna/intern/rna_nodetree.c
index 59570c10ebd..a148efb859d 100644
--- a/source/blender/makesrna/intern/rna_nodetree.c
+++ b/source/blender/makesrna/intern/rna_nodetree.c
@@ -3312,11 +3312,18 @@ static const EnumPropertyItem node_script_mode_items[] = {
 };
 
 static const EnumPropertyItem node_principled_distribution_items[] = {
-	{ SHD_GLOSSY_GGX, "GGX", 0, "GGX", "" },
-	{ SHD_GLOSSY_MULTI_GGX, "MULTI_GGX", 0, "Multiscatter GGX", "" },
+	{SHD_GLOSSY_GGX, "GGX", 0, "GGX", ""},
+	{SHD_GLOSSY_MULTI_GGX, "MULTI_GGX", 0, "Multiscatter GGX", ""},
+	{0, NULL, 0, NULL, NULL}
+};
+
+static const EnumPropertyItem node_subsurface_method_items[] = {
+	{SHD_SUBSURFACE_BURLEY, "BURLEY", 0, "Christensen-Burley", "Approximation to physically based volume scattering"},
+	{SHD_SUBSURFACE_RANDOM_WALK, "RANDOM_WALK", 0, "Random Walk", "Volumetric approximation to physically based volume scattering"},
 	{ 0, NULL, 0, NULL, NULL }
 };
 
+
 /* -- Common nodes ---------------------------------------------------------- */
 
 static void def_group_input(StructRNA *srna)
@@ -4263,6 +4270,12 @@ static void def_principled(StructRNA *srna)
 	RNA_def_property_enum_items(prop, node_principled_distribution_items);
 	RNA_def_property_ui_text(prop, "Distribution", "");
 	RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_ShaderNodePrincipled_update");
+
+	prop = RNA_def_property(srna, "subsurface_method", PROP_ENUM, PROP_NONE);
+	RNA_def_property_enum_sdna(prop, NULL, "custom2");
+	RNA_def_property_enum_items(prop, node_subsurface_method_items);
+	RNA_def_property_ui_text(prop, "Subsurface Method", "Method for rendering subsurface scattering");
+	RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_ShaderNodePrincipled_update");
 }
 
 static void def_refraction(StructRNA *srna)
@@ -4466,6 +4479,7 @@ static void def_sh_subsurface(StructRNA *srna)
 		{SHD_SUBSURFACE_CUBIC, "CUBIC", 0, "Cubic", "Simple cubic falloff function"},
 		{SHD_SUBSURFACE_GAUSSIAN, "GAUSSIAN", 0, "Gaussian", "Normal distribution, multiple can be combined to fit more complex profiles"},
 		{SHD_SUBSURFACE_BURLEY, "BURLEY", 0, "Christensen-Burley", "Approximation to physically based volume scattering"},
+		{SHD_SUBSURFACE_RANDOM_WALK, "RANDOM_WALK", 0, "Random Walk", "Volumetric approximation to physically based volume scattering"},
 		{0, NULL, 0, NULL, NULL}
 	};
 
diff --git a/source/blender/nodes/shader/nodes/node_shader_bsdf_principled.c b/source/blender/nodes/shader/nodes/node_shader_bsdf_principled.c
index b0ca4128d19..1c291cb5b83 100644
--- a/source/blender/nodes/shader/nodes/node_shader_bsdf_principled.c
+++ b/source/blender/nodes/shader/nodes/node_shader_bsdf_principled.c
@@ -61,6 +61,7 @@ static bNodeSocketTemplate sh_node_bsdf_principled_out[] = {
 static void node_shader_init_principled(bNodeTree *UNUSED(ntree), bNode *node)
 {
 	node->custom1 = SHD_GLOSSY_MULTI_GGX;
+	node->custom2 = SHD_SUBSURFACE_BURLEY;
 }
 
 static int node_shader_gpu_bsdf_principled(GPUMaterial *mat, bNode *node, bNodeExecData *UNUSED(execdata), GPUNodeStack *in, GPUNodeStack *out)