Cycles: use object coordinates when generated coordinates are missing

This modifies the attribute lookup to use object coordinates if no
generated coordinates are found on the geometry.

This is useful to avoid creating and copying this attribute, thus saving
a bit of time and memory.

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D12238

2 files changed, 51 insertions, 1 deletions

diff --git a/intern/cycles/kernel/shaders/node_texture_coordinate.osl b/intern/cycles/kernel/shaders/node_texture_coordinate.osl
index ac05e984af2..9cdb925dbfa 100644
--- a/intern/cycles/kernel/shaders/node_texture_coordinate.osl
+++ b/intern/cycles/kernel/shaders/node_texture_coordinate.osl
@@ -58,7 +58,9 @@ shader node_texture_coordinate(
       getattribute("geom:uv", UV);
     }
     else {
-      getattribute("geom:generated", Generated);
+      if (!getattribute("geom:generated", Generated)) {
+        Generated = transform("object", P);
+      }
       getattribute("geom:uv", UV);
     }
 
diff --git a/intern/cycles/kernel/svm/svm_attribute.h b/intern/cycles/kernel/svm/svm_attribute.h
index f598bfb8f8f..62740824ad1 100644
--- a/intern/cycles/kernel/svm/svm_attribute.h
+++ b/intern/cycles/kernel/svm/svm_attribute.h
@@ -72,6 +72,22 @@ ccl_device void svm_node_attr(KernelGlobals *kg, ShaderData *sd, float *stack, u
   }
 #endif
 
+  if (node.y == ATTR_STD_GENERATED && desc.element == ATTR_ELEMENT_NONE) {
+    /* No generated attribute, fall back to object coordinates. */
+    float3 f = sd->P;
+    object_inverse_position_transform(kg, sd, &f);
+    if (type == NODE_ATTR_OUTPUT_FLOAT) {
+      stack_store_float(stack, out_offset, average(f));
+    }
+    else if (type == NODE_ATTR_OUTPUT_FLOAT3) {
+      stack_store_float3(stack, out_offset, f);
+    }
+    else {
+      stack_store_float(stack, out_offset, 1.0f);
+    }
+    return;
+  }
+
   /* Surface. */
   if (desc.type == NODE_ATTR_FLOAT) {
     float f = primitive_surface_attribute_float(kg, sd, desc, NULL, NULL);
@@ -145,6 +161,22 @@ ccl_device void svm_node_attr_bump_dx(KernelGlobals *kg, ShaderData *sd, float *
   }
 #endif
 
+  if (node.y == ATTR_STD_GENERATED && desc.element == ATTR_ELEMENT_NONE) {
+    /* No generated attribute, fall back to object coordinates. */
+    float3 f = sd->P + sd->dP.dx;
+    object_inverse_position_transform(kg, sd, &f);
+    if (type == NODE_ATTR_OUTPUT_FLOAT) {
+      stack_store_float(stack, out_offset, average(f));
+    }
+    else if (type == NODE_ATTR_OUTPUT_FLOAT3) {
+      stack_store_float3(stack, out_offset, f);
+    }
+    else {
+      stack_store_float(stack, out_offset, 1.0f);
+    }
+    return;
+  }
+
   /* Surface */
   if (desc.type == NODE_ATTR_FLOAT) {
     float dx;
@@ -222,6 +254,22 @@ ccl_device void svm_node_attr_bump_dy(KernelGlobals *kg, ShaderData *sd, float *
   }
 #endif
 
+  if (node.y == ATTR_STD_GENERATED && desc.element == ATTR_ELEMENT_NONE) {
+    /* No generated attribute, fall back to object coordinates. */
+    float3 f = sd->P + sd->dP.dy;
+    object_inverse_position_transform(kg, sd, &f);
+    if (type == NODE_ATTR_OUTPUT_FLOAT) {
+      stack_store_float(stack, out_offset, average(f));
+    }
+    else if (type == NODE_ATTR_OUTPUT_FLOAT3) {
+      stack_store_float3(stack, out_offset, f);
+    }
+    else {
+      stack_store_float(stack, out_offset, 1.0f);
+    }
+    return;
+  }
+
   /* Surface */
   if (desc.type == NODE_ATTR_FLOAT) {
     float dy;