1 files changed, 50 insertions, 11 deletions

diff --git a/intern/cycles/render/attribute.cpp b/intern/cycles/render/attribute.cpp
index d6a638fd4cd..bf9d69cb47e 100644
--- a/intern/cycles/render/attribute.cpp
+++ b/intern/cycles/render/attribute.cpp
@@ -383,6 +383,23 @@ AttributeStandard Attribute::name_standard(const char *name)
   return ATTR_STD_NONE;
 }
 
+AttrKernelDataType Attribute::kernel_type(const Attribute &attr)
+{
+  if (attr.element == ATTR_ELEMENT_CORNER) {
+    return AttrKernelDataType::UCHAR4;
+  }
+
+  if (attr.type == TypeDesc::TypeFloat) {
+    return AttrKernelDataType::FLOAT;
+  }
+
+  if (attr.type == TypeFloat2) {
+    return AttrKernelDataType::FLOAT2;
+  }
+
+  return AttrKernelDataType::FLOAT3;
+}
+
 void Attribute::get_uv_tiles(Geometry *geom,
                              AttributePrimitive prim,
                              unordered_set<int> &tiles) const
@@ -417,7 +434,7 @@ void Attribute::get_uv_tiles(Geometry *geom,
 /* Attribute Set */
 
 AttributeSet::AttributeSet(Geometry *geometry, AttributePrimitive prim)
-    : geometry(geometry), prim(prim)
+    : modified_flag(~0u), geometry(geometry), prim(prim)
 {
 }
 
@@ -440,7 +457,7 @@ Attribute *AttributeSet::add(ustring name, TypeDesc type, AttributeElement eleme
 
   Attribute new_attr(name, type, element, geometry, prim);
   attributes.emplace_back(std::move(new_attr));
-  modified = true;
+  tag_modified(attributes.back());
   return &attributes.back();
 }
 
@@ -462,8 +479,7 @@ void AttributeSet::remove(ustring name)
 
     for (it = attributes.begin(); it != attributes.end(); it++) {
       if (&*it == attr) {
-        modified = true;
-        attributes.erase(it);
+        remove(it);
         return;
       }
     }
@@ -608,8 +624,7 @@ void AttributeSet::remove(AttributeStandard std)
 
     for (it = attributes.begin(); it != attributes.end(); it++) {
       if (&*it == attr) {
-        modified = true;
-        attributes.erase(it);
+        remove(it);
         return;
       }
     }
@@ -634,6 +649,12 @@ void AttributeSet::remove(Attribute *attribute)
   }
 }
 
+void AttributeSet::remove(list<Attribute>::iterator it)
+{
+  tag_modified(*it);
+  attributes.erase(it);
+}
+
 void AttributeSet::resize(bool reserve_only)
 {
   foreach (Attribute &attr, attributes) {
@@ -674,15 +695,13 @@ void AttributeSet::update(AttributeSet &&new_attributes)
   for (it = attributes.begin(); it != attributes.end();) {
     if (it->std != ATTR_STD_NONE) {
       if (new_attributes.find(it->std) == nullptr) {
-        modified = true;
-        attributes.erase(it++);
+        remove(it++);
         continue;
       }
     }
     else if (it->name != "") {
       if (new_attributes.find(it->name) == nullptr) {
-        modified = true;
-        attributes.erase(it++);
+        remove(it++);
         continue;
       }
     }
@@ -699,7 +718,27 @@ void AttributeSet::clear_modified()
   foreach (Attribute &attr, attributes) {
     attr.modified = false;
   }
-  modified = false;
+
+  modified_flag = 0;
+}
+
+void AttributeSet::tag_modified(const Attribute &attr)
+{
+  /* Some attributes are not stored in the various kernel attribute arrays
+   * (DeviceScene::attribute_*), so the modified flags are only set if the associated standard
+   * corresponds to an attribute which will be stored in the kernel's attribute arrays. */
+  const bool modifies_device_array = (attr.std != ATTR_STD_FACE_NORMAL &&
+                                      attr.std != ATTR_STD_VERTEX_NORMAL);
+
+  if (modifies_device_array) {
+    AttrKernelDataType kernel_type = Attribute::kernel_type(attr);
+    modified_flag |= (1u << kernel_type);
+  }
+}
+
+bool AttributeSet::modified(AttrKernelDataType kernel_type) const
+{
+  return (modified_flag & (1u << kernel_type)) != 0;
 }
 
 /* AttributeRequest */