Shading: Add Vertex Color node.

This patch adds a new Vertex Color node. The node also returns the alpha
of the vertex color layer as an output.

Reviewers: brecht

Differential Revision: https://developer.blender.org/D5767

20 files changed, 535 insertions, 49 deletions

diff --git a/intern/cycles/blender/blender_mesh.cpp b/intern/cycles/blender/blender_mesh.cpp
index 551866f7fce..30417e85441 100644
--- a/intern/cycles/blender/blender_mesh.cpp
+++ b/intern/cycles/blender/blender_mesh.cpp
@@ -335,7 +335,7 @@ static void attr_create_vertex_color(Scene *scene, Mesh *mesh, BL::Mesh &b_mesh,
         continue;
 
       Attribute *attr = mesh->subd_attributes.add(
-          ustring(l->name().c_str()), TypeDesc::TypeColor, ATTR_ELEMENT_CORNER_BYTE);
+          ustring(l->name().c_str()), TypeRGBA, ATTR_ELEMENT_CORNER_BYTE);
 
       BL::Mesh::polygons_iterator p;
       uchar4 *cdata = attr->data_uchar4();
@@ -343,9 +343,9 @@ static void attr_create_vertex_color(Scene *scene, Mesh *mesh, BL::Mesh &b_mesh,
       for (b_mesh.polygons.begin(p); p != b_mesh.polygons.end(); ++p) {
         int n = p->loop_total();
         for (int i = 0; i < n; i++) {
-          float3 color = get_float3(l->data[p->loop_start() + i].color());
+          float4 color = get_float4(l->data[p->loop_start() + i].color());
           /* Compress/encode vertex color using the sRGB curve. */
-          *(cdata++) = color_float_to_byte(color_srgb_to_linear_v3(color));
+          *(cdata++) = color_float4_to_uchar4(color_srgb_to_linear_v4(color));
         }
       }
     }
@@ -357,21 +357,21 @@ static void attr_create_vertex_color(Scene *scene, Mesh *mesh, BL::Mesh &b_mesh,
         continue;
 
       Attribute *attr = mesh->attributes.add(
-          ustring(l->name().c_str()), TypeDesc::TypeColor, ATTR_ELEMENT_CORNER_BYTE);
+          ustring(l->name().c_str()), TypeRGBA, ATTR_ELEMENT_CORNER_BYTE);
 
       BL::Mesh::loop_triangles_iterator t;
       uchar4 *cdata = attr->data_uchar4();
 
       for (b_mesh.loop_triangles.begin(t); t != b_mesh.loop_triangles.end(); ++t) {
         int3 li = get_int3(t->loops());
-        float3 c1 = get_float3(l->data[li[0]].color());
-        float3 c2 = get_float3(l->data[li[1]].color());
-        float3 c3 = get_float3(l->data[li[2]].color());
+        float4 c1 = get_float4(l->data[li[0]].color());
+        float4 c2 = get_float4(l->data[li[1]].color());
+        float4 c3 = get_float4(l->data[li[2]].color());
 
         /* Compress/encode vertex color using the sRGB curve. */
-        cdata[0] = color_float_to_byte(color_srgb_to_linear_v3(c1));
-        cdata[1] = color_float_to_byte(color_srgb_to_linear_v3(c2));
-        cdata[2] = color_float_to_byte(color_srgb_to_linear_v3(c3));
+        cdata[0] = color_float4_to_uchar4(color_srgb_to_linear_v4(c1));
+        cdata[1] = color_float4_to_uchar4(color_srgb_to_linear_v4(c2));
+        cdata[2] = color_float4_to_uchar4(color_srgb_to_linear_v4(c3));
         cdata += 3;
       }
     }
diff --git a/intern/cycles/blender/blender_shader.cpp b/intern/cycles/blender/blender_shader.cpp
index 257c799a3e0..362155f22ac 100644
--- a/intern/cycles/blender/blender_shader.cpp
+++ b/intern/cycles/blender/blender_shader.cpp
@@ -590,6 +590,12 @@ static ShaderNode *add_node(Scene *scene,
   else if (b_node.is_a(&RNA_ShaderNodeVolumeInfo)) {
     node = new VolumeInfoNode();
   }
+  else if (b_node.is_a(&RNA_ShaderNodeVertexColor)) {
+    BL::ShaderNodeVertexColor b_vertex_color_node(b_node);
+    VertexColorNode *vertex_color_node = new VertexColorNode();
+    vertex_color_node->layer_name = b_vertex_color_node.layer_name();
+    node = vertex_color_node;
+  }
   else if (b_node.is_a(&RNA_ShaderNodeBump)) {
     BL::ShaderNodeBump b_bump_node(b_node);
     BumpNode *bump = new BumpNode();
diff --git a/intern/cycles/kernel/CMakeLists.txt b/intern/cycles/kernel/CMakeLists.txt
index 04df49aa058..41e57bb3e43 100644
--- a/intern/cycles/kernel/CMakeLists.txt
+++ b/intern/cycles/kernel/CMakeLists.txt
@@ -223,6 +223,7 @@ set(SRC_SVM_HEADERS
   svm/svm_voxel.h
   svm/svm_wave.h
   svm/svm_white_noise.h
+  svm/svm_vertex_color.h
 )
 
 set(SRC_GEOM_HEADERS
diff --git a/intern/cycles/kernel/geom/geom_patch.h b/intern/cycles/kernel/geom/geom_patch.h
index df19199f68e..8b4b91b96c8 100644
--- a/intern/cycles/kernel/geom/geom_patch.h
+++ b/intern/cycles/kernel/geom/geom_patch.h
@@ -380,15 +380,15 @@ ccl_device float3 patch_eval_float3(KernelGlobals *kg,
   return val;
 }
 
-ccl_device float3 patch_eval_uchar4(KernelGlobals *kg,
+ccl_device float4 patch_eval_uchar4(KernelGlobals *kg,
                                     const ShaderData *sd,
                                     int offset,
                                     int patch,
                                     float u,
                                     float v,
                                     int channel,
-                                    float3 *du,
-                                    float3 *dv)
+                                    float4 *du,
+                                    float4 *dv)
 {
   int indices[PATCH_MAX_CONTROL_VERTS];
   float weights[PATCH_MAX_CONTROL_VERTS];
@@ -398,14 +398,14 @@ ccl_device float3 patch_eval_uchar4(KernelGlobals *kg,
   int num_control = patch_eval_control_verts(
       kg, sd->object, patch, u, v, channel, indices, weights, weights_du, weights_dv);
 
-  float3 val = make_float3(0.0f, 0.0f, 0.0f);
+  float4 val = make_float4(0.0f, 0.0f, 0.0f, 0.0f);
   if (du)
-    *du = make_float3(0.0f, 0.0f, 0.0f);
+    *du = make_float4(0.0f, 0.0f, 0.0f, 0.0f);
   if (dv)
-    *dv = make_float3(0.0f, 0.0f, 0.0f);
+    *dv = make_float4(0.0f, 0.0f, 0.0f, 0.0f);
 
   for (int i = 0; i < num_control; i++) {
-    float3 v = color_byte_to_float(kernel_tex_fetch(__attributes_uchar4, offset + indices[i]));
+    float4 v = color_uchar4_to_float4(kernel_tex_fetch(__attributes_uchar4, offset + indices[i]));
 
     val += v * weights[i];
     if (du)
diff --git a/intern/cycles/kernel/geom/geom_primitive.h b/intern/cycles/kernel/geom/geom_primitive.h
index 7f2b52a24c4..9a91da79f58 100644
--- a/intern/cycles/kernel/geom/geom_primitive.h
+++ b/intern/cycles/kernel/geom/geom_primitive.h
@@ -162,6 +162,27 @@ ccl_device_inline float3 primitive_attribute_float3(KernelGlobals *kg,
   }
 }
 
+ccl_device_inline float4 primitive_attribute_float4(KernelGlobals *kg,
+                                                    const ShaderData *sd,
+                                                    const AttributeDescriptor desc,
+                                                    float4 *dx,
+                                                    float4 *dy)
+{
+  if (sd->type & PRIMITIVE_ALL_TRIANGLE) {
+    if (subd_triangle_patch(kg, sd) == ~0)
+      return triangle_attribute_float4(kg, sd, desc, dx, dy);
+    else
+      return subd_triangle_attribute_float4(kg, sd, desc, dx, dy);
+  }
+  else {
+    if (dx)
+      *dx = make_float4(0.0f, 0.0f, 0.0f, 0.0f);
+    if (dy)
+      *dy = make_float4(0.0f, 0.0f, 0.0f, 0.0f);
+    return make_float4(0.0f, 0.0f, 0.0f, 0.0f);
+  }
+}
+
 ccl_device_inline float2 primitive_surface_attribute_float2(KernelGlobals *kg,
                                                             const ShaderData *sd,
                                                             const AttributeDescriptor desc,
diff --git a/intern/cycles/kernel/geom/geom_subd_triangle.h b/intern/cycles/kernel/geom/geom_subd_triangle.h
index 8d5b3c12833..81bac6e6ee1 100644
--- a/intern/cycles/kernel/geom/geom_subd_triangle.h
+++ b/intern/cycles/kernel/geom/geom_subd_triangle.h
@@ -382,13 +382,7 @@ ccl_device_noinline float3 subd_triangle_attribute_float3(KernelGlobals *kg,
     float2 p = dpdu * sd->u + dpdv * sd->v + uv[2];
 
     float3 a, dads, dadt;
-
-    if (desc.element == ATTR_ELEMENT_CORNER_BYTE) {
-      a = patch_eval_uchar4(kg, sd, desc.offset, patch, p.x, p.y, 0, &dads, &dadt);
-    }
-    else {
-      a = patch_eval_float3(kg, sd, desc.offset, patch, p.x, p.y, 0, &dads, &dadt);
-    }
+    a = patch_eval_float3(kg, sd, desc.offset, patch, p.x, p.y, 0, &dads, &dadt);
 
 #  ifdef __RAY_DIFFERENTIALS__
     if (dx || dy) {
@@ -460,7 +454,7 @@ ccl_device_noinline float3 subd_triangle_attribute_float3(KernelGlobals *kg,
 
     return sd->u * a + sd->v * b + (1.0f - sd->u - sd->v) * c;
   }
-  else if (desc.element == ATTR_ELEMENT_CORNER || desc.element == ATTR_ELEMENT_CORNER_BYTE) {
+  else if (desc.element == ATTR_ELEMENT_CORNER) {
     float2 uv[3];
     subd_triangle_patch_uv(kg, sd, uv);
 
@@ -469,18 +463,10 @@ ccl_device_noinline float3 subd_triangle_attribute_float3(KernelGlobals *kg,
 
     float3 f0, f1, f2, f3;
 
-    if (desc.element == ATTR_ELEMENT_CORNER) {
-      f0 = float4_to_float3(kernel_tex_fetch(__attributes_float3, corners[0] + desc.offset));
-      f1 = float4_to_float3(kernel_tex_fetch(__attributes_float3, corners[1] + desc.offset));
-      f2 = float4_to_float3(kernel_tex_fetch(__attributes_float3, corners[2] + desc.offset));
-      f3 = float4_to_float3(kernel_tex_fetch(__attributes_float3, corners[3] + desc.offset));
-    }
-    else {
-      f0 = color_byte_to_float(kernel_tex_fetch(__attributes_uchar4, corners[0] + desc.offset));
-      f1 = color_byte_to_float(kernel_tex_fetch(__attributes_uchar4, corners[1] + desc.offset));
-      f2 = color_byte_to_float(kernel_tex_fetch(__attributes_uchar4, corners[2] + desc.offset));
-      f3 = color_byte_to_float(kernel_tex_fetch(__attributes_uchar4, corners[3] + desc.offset));
-    }
+    f0 = float4_to_float3(kernel_tex_fetch(__attributes_float3, corners[0] + desc.offset));
+    f1 = float4_to_float3(kernel_tex_fetch(__attributes_float3, corners[1] + desc.offset));
+    f2 = float4_to_float3(kernel_tex_fetch(__attributes_float3, corners[2] + desc.offset));
+    f3 = float4_to_float3(kernel_tex_fetch(__attributes_float3, corners[3] + desc.offset));
 
     if (subd_triangle_patch_num_corners(kg, patch) != 4) {
       f1 = (f1 + f0) * 0.5f;
@@ -510,4 +496,102 @@ ccl_device_noinline float3 subd_triangle_attribute_float3(KernelGlobals *kg,
   }
 }
 
+ccl_device_noinline float4 subd_triangle_attribute_float4(KernelGlobals *kg,
+                                                          const ShaderData *sd,
+                                                          const AttributeDescriptor desc,
+                                                          float4 *dx,
+                                                          float4 *dy)
+{
+  int patch = subd_triangle_patch(kg, sd);
+
+#ifdef __PATCH_EVAL__
+  if (desc.flags & ATTR_SUBDIVIDED) {
+    float2 uv[3];
+    subd_triangle_patch_uv(kg, sd, uv);
+
+    float2 dpdu = uv[0] - uv[2];
+    float2 dpdv = uv[1] - uv[2];
+
+    /* p is [s, t] */
+    float2 p = dpdu * sd->u + dpdv * sd->v + uv[2];
+
+    float4 dads, dadt;
+
+    float4 a = patch_eval_uchar4(kg, sd, desc.offset, patch, p.x, p.y, 0, &dads, &dadt);
+
+#  ifdef __RAY_DIFFERENTIALS__
+    if (dx || dy) {
+      float dsdu = dpdu.x;
+      float dtdu = dpdu.y;
+      float dsdv = dpdv.x;
+      float dtdv = dpdv.y;
+
+      if (dx) {
+        float dudx = sd->du.dx;
+        float dvdx = sd->dv.dx;
+
+        float dsdx = dsdu * dudx + dsdv * dvdx;
+        float dtdx = dtdu * dudx + dtdv * dvdx;
+
+        *dx = dads * dsdx + dadt * dtdx;
+      }
+      if (dy) {
+        float dudy = sd->du.dy;
+        float dvdy = sd->dv.dy;
+
+        float dsdy = dsdu * dudy + dsdv * dvdy;
+        float dtdy = dtdu * dudy + dtdv * dvdy;
+
+        *dy = dads * dsdy + dadt * dtdy;
+      }
+    }
+#  endif
+    return a;
+  }
+  else
+#endif /* __PATCH_EVAL__ */
+      if (desc.element == ATTR_ELEMENT_CORNER_BYTE) {
+    float2 uv[3];
+    subd_triangle_patch_uv(kg, sd, uv);
+
+    int corners[4];
+    subd_triangle_patch_corners(kg, patch, corners);
+
+    float4 f0 = color_uchar4_to_float4(
+        kernel_tex_fetch(__attributes_uchar4, corners[0] + desc.offset));
+    float4 f1 = color_uchar4_to_float4(
+        kernel_tex_fetch(__attributes_uchar4, corners[1] + desc.offset));
+    float4 f2 = color_uchar4_to_float4(
+        kernel_tex_fetch(__attributes_uchar4, corners[2] + desc.offset));
+    float4 f3 = color_uchar4_to_float4(
+        kernel_tex_fetch(__attributes_uchar4, corners[3] + desc.offset));
+
+    if (subd_triangle_patch_num_corners(kg, patch) != 4) {
+      f1 = (f1 + f0) * 0.5f;
+      f3 = (f3 + f0) * 0.5f;
+    }
+
+    float4 a = mix(mix(f0, f1, uv[0].x), mix(f3, f2, uv[0].x), uv[0].y);
+    float4 b = mix(mix(f0, f1, uv[1].x), mix(f3, f2, uv[1].x), uv[1].y);
+    float4 c = mix(mix(f0, f1, uv[2].x), mix(f3, f2, uv[2].x), uv[2].y);
+
+#ifdef __RAY_DIFFERENTIALS__
+    if (dx)
+      *dx = sd->du.dx * a + sd->dv.dx * b - (sd->du.dx + sd->dv.dx) * c;
+    if (dy)
+      *dy = sd->du.dy * a + sd->dv.dy * b - (sd->du.dy + sd->dv.dy) * c;
+#endif
+
+    return sd->u * a + sd->v * b + (1.0f - sd->u - sd->v) * c;
+  }
+  else {
+    if (dx)
+      *dx = make_float4(0.0f, 0.0f, 0.0f, 0.0f);
+    if (dy)
+      *dy = make_float4(0.0f, 0.0f, 0.0f, 0.0f);
+
+    return make_float4(0.0f, 0.0f, 0.0f, 0.0f);
+  }
+}
+
 CCL_NAMESPACE_END
diff --git a/intern/cycles/kernel/geom/geom_triangle.h b/intern/cycles/kernel/geom/geom_triangle.h
index 9938c0ba2c3..fdb7f655f64 100644
--- a/intern/cycles/kernel/geom/geom_triangle.h
+++ b/intern/cycles/kernel/geom/geom_triangle.h
@@ -255,20 +255,13 @@ ccl_device float3 triangle_attribute_float3(KernelGlobals *kg,
 
     return sd->u * f0 + sd->v * f1 + (1.0f - sd->u - sd->v) * f2;
   }
-  else if (desc.element == ATTR_ELEMENT_CORNER || desc.element == ATTR_ELEMENT_CORNER_BYTE) {
+  else if (desc.element == ATTR_ELEMENT_CORNER) {
     int tri = desc.offset + sd->prim * 3;
     float3 f0, f1, f2;
 
-    if (desc.element == ATTR_ELEMENT_CORNER) {
-      f0 = float4_to_float3(kernel_tex_fetch(__attributes_float3, tri + 0));
-      f1 = float4_to_float3(kernel_tex_fetch(__attributes_float3, tri + 1));
-      f2 = float4_to_float3(kernel_tex_fetch(__attributes_float3, tri + 2));
-    }
-    else {
-      f0 = color_byte_to_float(kernel_tex_fetch(__attributes_uchar4, tri + 0));
-      f1 = color_byte_to_float(kernel_tex_fetch(__attributes_uchar4, tri + 1));
-      f2 = color_byte_to_float(kernel_tex_fetch(__attributes_uchar4, tri + 2));
-    }
+    f0 = float4_to_float3(kernel_tex_fetch(__attributes_float3, tri + 0));
+    f1 = float4_to_float3(kernel_tex_fetch(__attributes_float3, tri + 1));
+    f2 = float4_to_float3(kernel_tex_fetch(__attributes_float3, tri + 2));
 
 #ifdef __RAY_DIFFERENTIALS__
     if (dx)
@@ -289,4 +282,36 @@ ccl_device float3 triangle_attribute_float3(KernelGlobals *kg,
   }
 }
 
+ccl_device float4 triangle_attribute_float4(KernelGlobals *kg,
+                                            const ShaderData *sd,
+                                            const AttributeDescriptor desc,
+                                            float4 *dx,
+                                            float4 *dy)
+{
+  if (desc.element == ATTR_ELEMENT_CORNER_BYTE) {
+    int tri = desc.offset + sd->prim * 3;
+
+    float4 f0 = color_uchar4_to_float4(kernel_tex_fetch(__attributes_uchar4, tri + 0));
+    float4 f1 = color_uchar4_to_float4(kernel_tex_fetch(__attributes_uchar4, tri + 1));
+    float4 f2 = color_uchar4_to_float4(kernel_tex_fetch(__attributes_uchar4, tri + 2));
+
+#ifdef __RAY_DIFFERENTIALS__
+    if (dx)
+      *dx = sd->du.dx * f0 + sd->dv.dx * f1 - (sd->du.dx + sd->dv.dx) * f2;
+    if (dy)
+      *dy = sd->du.dy * f0 + sd->dv.dy * f1 - (sd->du.dy + sd->dv.dy) * f2;
+#endif
+
+    return sd->u * f0 + sd->v * f1 + (1.0f - sd->u - sd->v) * f2;
+  }
+  else {
+    if (dx)
+      *dx = make_float4(0.0f, 0.0f, 0.0f, 0.0f);
+    if (dy)
+      *dy = make_float4(0.0f, 0.0f, 0.0f, 0.0f);
+
+    return make_float4(0.0f, 0.0f, 0.0f, 0.0f);
+  }
+}
+
 CCL_NAMESPACE_END
diff --git a/intern/cycles/kernel/osl/osl_services.cpp b/intern/cycles/kernel/osl/osl_services.cpp
index 415de9cd66b..2698ed59e64 100644
--- a/intern/cycles/kernel/osl/osl_services.cpp
+++ b/intern/cycles/kernel/osl/osl_services.cpp
@@ -483,6 +483,65 @@ static bool set_attribute_float3(float3 f, TypeDesc type, bool derivatives, void
   return set_attribute_float3(fv, type, derivatives, val);
 }
 
+/* Attributes with the TypeRGBA type descriptor should be retrived and stored
+ * in a float array of size 4 (e.g. node_vertex_color.osl), this array have
+ * a type descriptor TypeFloatArray4. If the storage is not a TypeFloatArray4,
+ * we either store the first three components in a vector, store the average of
+ * the components in a float, or fail the retrival and do nothing. We allow
+ * this for the correct operation of the Attribute node.
+ */
+
+static bool set_attribute_float4(float4 f[3], TypeDesc type, bool derivatives, void *val)
+{
+  float *fval = (float *)val;
+  if (type == TypeFloatArray4) {
+    fval[0] = f[0].x;
+    fval[1] = f[0].y;
+    fval[2] = f[0].z;
+    fval[3] = f[0].w;
+
+    if (derivatives) {
+      fval[4] = f[1].x;
+      fval[5] = f[1].y;
+      fval[6] = f[1].z;
+      fval[7] = f[1].w;
+
+      fval[8] = f[2].x;
+      fval[9] = f[2].y;
+      fval[10] = f[2].z;
+      fval[11] = f[2].w;
+    }
+    return true;
+  }
+  else if (type == TypeDesc::TypePoint || type == TypeDesc::TypeVector ||
+           type == TypeDesc::TypeNormal || type == TypeDesc::TypeColor) {
+    fval[0] = f[0].x;
+    fval[1] = f[0].y;
+    fval[2] = f[0].z;
+
+    if (derivatives) {
+      fval[3] = f[1].x;
+      fval[4] = f[1].y;
+      fval[5] = f[1].z;
+
+      fval[6] = f[2].x;
+      fval[7] = f[2].y;
+      fval[8] = f[2].z;
+    }
+    return true;
+  }
+  else if (type == TypeDesc::TypeFloat) {
+    fval[0] = average(float4_to_float3(f[0]));
+
+    if (derivatives) {
+      fval[1] = average(float4_to_float3(f[1]));
+      fval[2] = average(float4_to_float3(f[2]));
+    }
+    return true;
+  }
+  return false;
+}
+
 static bool set_attribute_float(float f[3], TypeDesc type, bool derivatives, void *val)
 {
   if (type == TypeDesc::TypePoint || type == TypeDesc::TypeVector ||
@@ -629,6 +688,12 @@ static bool get_primitive_attribute(KernelGlobals *kg,
         kg, sd, attr.desc, (derivatives) ? &fval[1] : NULL, (derivatives) ? &fval[2] : NULL);
     return set_attribute_float(fval, type, derivatives, val);
   }
+  else if (attr.type == TypeRGBA) {
+    float4 fval[3];
+    fval[0] = primitive_attribute_float4(
+        kg, sd, attr.desc, (derivatives) ? &fval[1] : NULL, (derivatives) ? &fval[2] : NULL);
+    return set_attribute_float4(fval, type, derivatives, val);
+  }
   else {
     return false;
   }
diff --git a/intern/cycles/kernel/shaders/CMakeLists.txt b/intern/cycles/kernel/shaders/CMakeLists.txt
index 38ba113a184..f4258da70d3 100644
--- a/intern/cycles/kernel/shaders/CMakeLists.txt
+++ b/intern/cycles/kernel/shaders/CMakeLists.txt
@@ -80,6 +80,7 @@ set(SRC_OSL
   node_vector_math.osl
   node_vector_transform.osl
   node_velvet_bsdf.osl
+  node_vertex_color.osl
   node_voronoi_texture.osl
   node_voxel_texture.osl
   node_wavelength.osl
diff --git a/intern/cycles/kernel/shaders/node_vertex_color.osl b/intern/cycles/kernel/shaders/node_vertex_color.osl
new file mode 100644
index 00000000000..1997a690181
--- /dev/null
+++ b/intern/cycles/kernel/shaders/node_vertex_color.osl
@@ -0,0 +1,40 @@
+/*
+ * Copyright 2011-2013 Blender Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "stdosl.h"
+
+shader node_vertex_color(string bump_offset = "center",
+                         string layer_name = "",
+                         output color Color = 0.0,
+                         output float Alpha = 0.0)
+{
+  float vertex_color[4];
+  if (getattribute(layer_name, vertex_color)) {
+    Color = color(vertex_color[0], vertex_color[1], vertex_color[2]);
+    Alpha = vertex_color[3];
+
+    if (bump_offset == "dx") {
+      Color += Dx(Color);
+      Alpha += Dx(Alpha);
+    }
+    else if (bump_offset == "dy") {
+      Color += Dy(Color);
+      Alpha += Dy(Alpha);
+    }
+  } else {
+    warning("%s", "Invalid attribute.");
+  }
+}
diff --git a/intern/cycles/kernel/svm/svm.h b/intern/cycles/kernel/svm/svm.h
index 8de66a04963..4fc5e633e3b 100644
--- a/intern/cycles/kernel/svm/svm.h
+++ b/intern/cycles/kernel/svm/svm.h
@@ -205,6 +205,7 @@ CCL_NAMESPACE_END
 #include "kernel/svm/svm_map_range.h"
 #include "kernel/svm/svm_clamp.h"
 #include "kernel/svm/svm_white_noise.h"
+#include "kernel/svm/svm_vertex_color.h"
 
 #ifdef __SHADER_RAYTRACE__
 #  include "kernel/svm/svm_ao.h"
@@ -289,6 +290,9 @@ ccl_device_noinline void svm_eval_nodes(KernelGlobals *kg,
       case NODE_ATTR:
         svm_node_attr(kg, sd, stack, node);
         break;
+      case NODE_VERTEX_COLOR:
+        svm_node_vertex_color(kg, sd, stack, node.y, node.z, node.w);
+        break;
 #  if NODES_FEATURE(NODE_FEATURE_BUMP)
       case NODE_GEOMETRY_BUMP_DX:
         svm_node_geometry_bump_dx(kg, sd, stack, node.y, node.z);
@@ -328,6 +332,12 @@ ccl_device_noinline void svm_eval_nodes(KernelGlobals *kg,
       case NODE_ATTR_BUMP_DY:
         svm_node_attr_bump_dy(kg, sd, stack, node);
         break;
+      case NODE_VERTEX_COLOR_BUMP_DX:
+        svm_node_vertex_color_bump_dx(kg, sd, stack, node.y, node.z, node.w);
+        break;
+      case NODE_VERTEX_COLOR_BUMP_DY:
+        svm_node_vertex_color_bump_dy(kg, sd, stack, node.y, node.z, node.w);
+        break;
       case NODE_TEX_COORD_BUMP_DX:
         svm_node_tex_coord_bump_dx(kg, sd, path_flag, stack, node, &offset);
         break;
diff --git a/intern/cycles/kernel/svm/svm_attribute.h b/intern/cycles/kernel/svm/svm_attribute.h
index eaee0f9e4ee..fc7a3ba3f5a 100644
--- a/intern/cycles/kernel/svm/svm_attribute.h
+++ b/intern/cycles/kernel/svm/svm_attribute.h
@@ -69,6 +69,15 @@ ccl_device void svm_node_attr(KernelGlobals *kg, ShaderData *sd, float *stack, u
       stack_store_float3(stack, out_offset, make_float3(f.x, f.y, 0.0f));
     }
   }
+  else if (desc.type == NODE_ATTR_RGBA) {
+    float4 f = primitive_attribute_float4(kg, sd, desc, NULL, NULL);
+    if (type == NODE_ATTR_FLOAT) {
+      stack_store_float(stack, out_offset, average(float4_to_float3(f)));
+    }
+    else {
+      stack_store_float3(stack, out_offset, float4_to_float3(f));
+    }
+  }
   else {
     float3 f = primitive_attribute_float3(kg, sd, desc, NULL, NULL);
     if (type == NODE_ATTR_FLOAT) {
@@ -107,6 +116,16 @@ ccl_device void svm_node_attr_bump_dx(KernelGlobals *kg, ShaderData *sd, float *
       stack_store_float3(stack, out_offset, make_float3(f.x + dx.x, f.y + dx.y, 0.0f));
     }
   }
+  else if (desc.type == NODE_ATTR_RGBA) {
+    float4 dx;
+    float4 f = primitive_attribute_float4(kg, sd, desc, &dx, NULL);
+    if (type == NODE_ATTR_FLOAT) {
+      stack_store_float(stack, out_offset, average(float4_to_float3(f + dx)));
+    }
+    else {
+      stack_store_float3(stack, out_offset, float4_to_float3(f + dx));
+    }
+  }
   else {
     float3 dx;
     float3 f = primitive_surface_attribute_float3(kg, sd, desc, &dx, NULL);
@@ -146,6 +165,16 @@ ccl_device void svm_node_attr_bump_dy(KernelGlobals *kg, ShaderData *sd, float *
       stack_store_float3(stack, out_offset, make_float3(f.x + dy.x, f.y + dy.y, 0.0f));
     }
   }
+  else if (desc.type == NODE_ATTR_RGBA) {
+    float4 dy;
+    float4 f = primitive_attribute_float4(kg, sd, desc, NULL, &dy);
+    if (type == NODE_ATTR_FLOAT) {
+      stack_store_float(stack, out_offset, average(float4_to_float3(f + dy)));
+    }
+    else {
+      stack_store_float3(stack, out_offset, float4_to_float3(f + dy));
+    }
+  }
   else {
     float3 dy;
     float3 f = primitive_surface_attribute_float3(kg, sd, desc, NULL, &dy);
diff --git a/intern/cycles/kernel/svm/svm_types.h b/intern/cycles/kernel/svm/svm_types.h
index 65e2dacedae..a6f2327dada 100644
--- a/intern/cycles/kernel/svm/svm_types.h
+++ b/intern/cycles/kernel/svm/svm_types.h
@@ -142,12 +142,16 @@ typedef enum ShaderNodeType {
   NODE_CLAMP,
   NODE_TEXTURE_MAPPING,
   NODE_TEX_WHITE_NOISE,
+  NODE_VERTEX_COLOR,
+  NODE_VERTEX_COLOR_BUMP_DX,
+  NODE_VERTEX_COLOR_BUMP_DY,
 } ShaderNodeType;
 
 typedef enum NodeAttributeType {
   NODE_ATTR_FLOAT = 0,
   NODE_ATTR_FLOAT2,
   NODE_ATTR_FLOAT3,
+  NODE_ATTR_RGBA,
   NODE_ATTR_MATRIX
 } NodeAttributeType;
 
diff --git a/intern/cycles/kernel/svm/svm_vertex_color.h b/intern/cycles/kernel/svm/svm_vertex_color.h
new file mode 100644
index 00000000000..3c105b1cbfa
--- /dev/null
+++ b/intern/cycles/kernel/svm/svm_vertex_color.h
@@ -0,0 +1,92 @@
+/*
+ * Copyright 2011-2013 Blender Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+CCL_NAMESPACE_BEGIN
+
+ccl_device void svm_node_vertex_color(KernelGlobals *kg,
+                                      ShaderData *sd,
+                                      float *stack,
+                                      uint layer_id,
+                                      uint color_offset,
+                                      uint alpha_offset)
+{
+  AttributeDescriptor descriptor = find_attribute(kg, sd, layer_id);
+  if (descriptor.offset != ATTR_STD_NOT_FOUND) {
+    float4 vertex_color = primitive_attribute_float4(kg, sd, descriptor, NULL, NULL);
+    stack_store_float3(stack, color_offset, float4_to_float3(vertex_color));
+    stack_store_float(stack, alpha_offset, vertex_color.w);
+  }
+  else {
+    stack_store_float3(stack, color_offset, make_float3(0.0f, 0.0f, 0.0f));
+    stack_store_float(stack, alpha_offset, 0.0f);
+  }
+}
+
+#ifndef __KERNEL_CUDA__
+ccl_device
+#else
+ccl_device_noinline
+#endif
+    void
+    svm_node_vertex_color_bump_dx(KernelGlobals *kg,
+                                  ShaderData *sd,
+                                  float *stack,
+                                  uint layer_id,
+                                  uint color_offset,
+                                  uint alpha_offset)
+{
+  AttributeDescriptor descriptor = find_attribute(kg, sd, layer_id);
+  if (descriptor.offset != ATTR_STD_NOT_FOUND) {
+    float4 dx;
+    float4 vertex_color = primitive_attribute_float4(kg, sd, descriptor, &dx, NULL);
+    vertex_color += dx;
+    stack_store_float3(stack, color_offset, float4_to_float3(vertex_color));
+    stack_store_float(stack, alpha_offset, vertex_color.w);
+  }
+  else {
+    stack_store_float3(stack, color_offset, make_float3(0.0f, 0.0f, 0.0f));
+    stack_store_float(stack, alpha_offset, 0.0f);
+  }
+}
+
+#ifndef __KERNEL_CUDA__
+ccl_device
+#else
+ccl_device_noinline
+#endif
+    void
+    svm_node_vertex_color_bump_dy(KernelGlobals *kg,
+                                  ShaderData *sd,
+                                  float *stack,
+                                  uint layer_id,
+                                  uint color_offset,
+                                  uint alpha_offset)
+{
+  AttributeDescriptor descriptor = find_attribute(kg, sd, layer_id);
+  if (descriptor.offset != ATTR_STD_NOT_FOUND) {
+    float4 dy;
+    float4 vertex_color = primitive_attribute_float4(kg, sd, descriptor, NULL, &dy);
+    vertex_color += dy;
+    stack_store_float3(stack, color_offset, float4_to_float3(vertex_color));
+    stack_store_float(stack, alpha_offset, vertex_color.w);
+  }
+  else {
+    stack_store_float3(stack, color_offset, make_float3(0.0f, 0.0f, 0.0f));
+    stack_store_float(stack, alpha_offset, 0.0f);
+  }
+}
+
+CCL_NAMESPACE_END
diff --git a/intern/cycles/render/attribute.cpp b/intern/cycles/render/attribute.cpp
index f1341d50b9d..0fa1142f354 100644
--- a/intern/cycles/render/attribute.cpp
+++ b/intern/cycles/render/attribute.cpp
@@ -48,7 +48,8 @@ void Attribute::set(ustring name_, TypeDesc type_, AttributeElement element_)
   /* string and matrix not supported! */
   assert(type == TypeDesc::TypeFloat || type == TypeDesc::TypeColor ||
          type == TypeDesc::TypePoint || type == TypeDesc::TypeVector ||
-         type == TypeDesc::TypeNormal || type == TypeDesc::TypeMatrix || type == TypeFloat2);
+         type == TypeDesc::TypeNormal || type == TypeDesc::TypeMatrix || type == TypeFloat2 ||
+         type == TypeRGBA);
 }
 
 void Attribute::resize(Mesh *mesh, AttributePrimitive prim, bool reserve_only)
diff --git a/intern/cycles/render/mesh.cpp b/intern/cycles/render/mesh.cpp
index 3d2cc98d38b..9be078b6fca 100644
--- a/intern/cycles/render/mesh.cpp
+++ b/intern/cycles/render/mesh.cpp
@@ -1223,6 +1223,8 @@ void MeshManager::update_osl_attributes(Device *device,
           osl_attr.type = TypeDesc::TypeMatrix;
         else if (req.triangle_type == TypeFloat2)
           osl_attr.type = TypeFloat2;
+        else if (req.triangle_type == TypeRGBA)
+          osl_attr.type = TypeRGBA;
         else
           osl_attr.type = TypeDesc::TypeColor;
 
@@ -1246,6 +1248,8 @@ void MeshManager::update_osl_attributes(Device *device,
           osl_attr.type = TypeDesc::TypeMatrix;
         else if (req.curve_type == TypeFloat2)
           osl_attr.type = TypeFloat2;
+        else if (req.curve_type == TypeRGBA)
+          osl_attr.type = TypeRGBA;
         else
           osl_attr.type = TypeDesc::TypeColor;
 
@@ -1269,6 +1273,8 @@ void MeshManager::update_osl_attributes(Device *device,
           osl_attr.type = TypeDesc::TypeMatrix;
         else if (req.subd_type == TypeFloat2)
           osl_attr.type = TypeFloat2;
+        else if (req.subd_type == TypeRGBA)
+          osl_attr.type = TypeRGBA;
         else
           osl_attr.type = TypeDesc::TypeColor;
 
@@ -1341,6 +1347,8 @@ void MeshManager::update_svm_attributes(Device *,
           attr_map[index].w = NODE_ATTR_MATRIX;
         else if (req.triangle_type == TypeFloat2)
           attr_map[index].w = NODE_ATTR_FLOAT2;
+        else if (req.triangle_type == TypeRGBA)
+          attr_map[index].w = NODE_ATTR_RGBA;
         else
           attr_map[index].w = NODE_ATTR_FLOAT3;
 
@@ -1379,6 +1387,8 @@ void MeshManager::update_svm_attributes(Device *,
           attr_map[index].w = NODE_ATTR_MATRIX;
         else if (req.subd_type == TypeFloat2)
           attr_map[index].w = NODE_ATTR_FLOAT2;
+        else if (req.triangle_type == TypeRGBA)
+          attr_map[index].w = NODE_ATTR_RGBA;
         else
           attr_map[index].w = NODE_ATTR_FLOAT3;
 
diff --git a/intern/cycles/render/nodes.cpp b/intern/cycles/render/nodes.cpp
index 1d98fabbc9f..71f1863ea49 100644
--- a/intern/cycles/render/nodes.cpp
+++ b/intern/cycles/render/nodes.cpp
@@ -4342,6 +4342,64 @@ void VolumeInfoNode::compile(OSLCompiler &)
 {
 }
 
+NODE_DEFINE(VertexColorNode)
+{
+  NodeType *type = NodeType::add("vertex_color", create, NodeType::SHADER);
+
+  SOCKET_STRING(layer_name, "Layer Name", ustring());
+  SOCKET_OUT_COLOR(color, "Color");
+  SOCKET_OUT_FLOAT(alpha, "Alpha");
+
+  return type;
+}
+
+VertexColorNode::VertexColorNode() : ShaderNode(node_type)
+{
+}
+
+void VertexColorNode::attributes(Shader *shader, AttributeRequestSet *attributes)
+{
+  if (!(output("Color")->links.empty() && output("Alpha")->links.empty())) {
+    attributes->add_standard(layer_name);
+  }
+  ShaderNode::attributes(shader, attributes);
+}
+
+void VertexColorNode::compile(SVMCompiler &compiler)
+{
+  ShaderOutput *color_out = output("Color");
+  ShaderOutput *alpha_out = output("Alpha");
+  int layer_id = compiler.attribute(layer_name);
+
+  ShaderNodeType node;
+
+  if (bump == SHADER_BUMP_DX)
+    node = NODE_VERTEX_COLOR_BUMP_DX;
+  else if (bump == SHADER_BUMP_DY)
+    node = NODE_VERTEX_COLOR_BUMP_DY;
+  else {
+    node = NODE_VERTEX_COLOR;
+  }
+
+  compiler.add_node(
+      node, layer_id, compiler.stack_assign(color_out), compiler.stack_assign(alpha_out));
+}
+
+void VertexColorNode::compile(OSLCompiler &compiler)
+{
+  if (bump == SHADER_BUMP_DX) {
+    compiler.parameter("bump_offset", "dx");
+  }
+  else if (bump == SHADER_BUMP_DY) {
+    compiler.parameter("bump_offset", "dy");
+  }
+  else {
+    compiler.parameter("bump_offset", "center");
+  }
+  compiler.parameter("layer_name", layer_name.c_str());
+  compiler.add(this, "node_vertex_color");
+}
+
 /* Value */
 
 NODE_DEFINE(ValueNode)
diff --git a/intern/cycles/render/nodes.h b/intern/cycles/render/nodes.h
index 171568644fb..13e9b65fa07 100644
--- a/intern/cycles/render/nodes.h
+++ b/intern/cycles/render/nodes.h
@@ -979,6 +979,22 @@ class VolumeInfoNode : public ShaderNode {
   void expand(ShaderGraph *graph);
 };
 
+class VertexColorNode : public ShaderNode {
+ public:
+  SHADER_NODE_CLASS(VertexColorNode)
+  void attributes(Shader *shader, AttributeRequestSet *attributes);
+  bool has_attribute_dependency()
+  {
+    return true;
+  }
+  bool has_spatial_varying()
+  {
+    return true;
+  }
+
+  ustring layer_name;
+};
+
 class ValueNode : public ShaderNode {
  public:
   SHADER_NODE_CLASS(ValueNode)
diff --git a/intern/cycles/util/util_color.h b/intern/cycles/util/util_color.h
index 6e61190de6b..c6937ca78fe 100644
--- a/intern/cycles/util/util_color.h
+++ b/intern/cycles/util/util_color.h
@@ -43,11 +43,29 @@ ccl_device uchar4 color_float_to_byte(float3 c)
   return make_uchar4(r, g, b, 0);
 }
 
+ccl_device uchar4 color_float4_to_uchar4(float4 c)
+{
+  uchar r, g, b, a;
+
+  r = float_to_byte(c.x);
+  g = float_to_byte(c.y);
+  b = float_to_byte(c.z);
+  a = float_to_byte(c.w);
+
+  return make_uchar4(r, g, b, a);
+}
+
 ccl_device_inline float3 color_byte_to_float(uchar4 c)
 {
   return make_float3(c.x * (1.0f / 255.0f), c.y * (1.0f / 255.0f), c.z * (1.0f / 255.0f));
 }
 
+ccl_device_inline float4 color_uchar4_to_float4(uchar4 c)
+{
+  return make_float4(
+      c.x * (1.0f / 255.0f), c.y * (1.0f / 255.0f), c.z * (1.0f / 255.0f), c.w * (1.0f / 255.0f));
+}
+
 ccl_device float color_srgb_to_linear(float c)
 {
   if (c < 0.04045f)
diff --git a/intern/cycles/util/util_param.h b/intern/cycles/util/util_param.h
index cfbe416aba1..3f8e2d6d700 100644
--- a/intern/cycles/util/util_param.h
+++ b/intern/cycles/util/util_param.h
@@ -29,6 +29,11 @@ CCL_NAMESPACE_BEGIN
 OIIO_NAMESPACE_USING
 
 static constexpr TypeDesc TypeFloat2(TypeDesc::FLOAT, TypeDesc::VEC2);
+static constexpr TypeDesc TypeRGBA(TypeDesc::FLOAT, TypeDesc::VEC4, TypeDesc::COLOR);
+static constexpr TypeDesc TypeFloatArray4(TypeDesc::FLOAT,
+                                          TypeDesc::SCALAR,
+                                          TypeDesc::NOSEMANTICS,
+                                          4);
 
 CCL_NAMESPACE_END