1 files changed, 37 insertions, 0 deletions
diff --git a/intern/cycles/kernel/geom/geom_patch.h b/intern/cycles/kernel/geom/geom_patch.h
index 8b4b91b96c8..1de05fa9e0d 100644
--- a/intern/cycles/kernel/geom/geom_patch.h
+++ b/intern/cycles/kernel/geom/geom_patch.h
@@ -380,6 +380,43 @@ ccl_device float3 patch_eval_float3(KernelGlobals *kg,
   return val;
 }
 
+ccl_device float4 patch_eval_float4(KernelGlobals *kg,
+                                    const ShaderData *sd,
+                                    int offset,
+                                    int patch,
+                                    float u,
+                                    float v,
+                                    int channel,
+                                    float4 *du,
+                                    float4 *dv)
+{
+  int indices[PATCH_MAX_CONTROL_VERTS];
+  float weights[PATCH_MAX_CONTROL_VERTS];
+  float weights_du[PATCH_MAX_CONTROL_VERTS];
+  float weights_dv[PATCH_MAX_CONTROL_VERTS];
+
+  int num_control = patch_eval_control_verts(
+      kg, sd->object, patch, u, v, channel, indices, weights, weights_du, weights_dv);
+
+  float4 val = make_float4(0.0f, 0.0f, 0.0f, 0.0f);
+  if (du)
+    *du = make_float4(0.0f, 0.0f, 0.0f, 0.0f);
+  if (dv)
+    *dv = make_float4(0.0f, 0.0f, 0.0f, 0.0f);
+
+  for (int i = 0; i < num_control; i++) {
+    float4 v = kernel_tex_fetch(__attributes_float3, offset + indices[i]);
+
+    val += v * weights[i];
+    if (du)
+      *du += v * weights_du[i];
+    if (dv)
+      *dv += v * weights_dv[i];
+  }
+
+  return val;
+}
+
 ccl_device float4 patch_eval_uchar4(KernelGlobals *kg,
                                     const ShaderData *sd,
                                     int offset,