Cycles microdisplacement: Support for Catmull-Clark subdivision via OpenSubdiv

Enables Catmull-Clark subdivision meshes with support for creases and attribute
subdivision. Still waiting on OpenSubdiv to fully support face varying
interpolation for subdividing uv coordinates tho. Also there may be some
inconsistencies with Blender's subdivision which will be resolved at a
later time.

Code for reading patch tables and creating patch maps is borrowed
from OpenSubdiv.

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D2111

1 files changed, 3 insertions, 2 deletions

diff --git a/intern/cycles/kernel/geom/geom_attribute.h b/intern/cycles/kernel/geom/geom_attribute.h
index e036c2752d7..8604d30ad34 100644
--- a/intern/cycles/kernel/geom/geom_attribute.h
+++ b/intern/cycles/kernel/geom/geom_attribute.h
@@ -45,7 +45,7 @@ ccl_device_inline uint attribute_primitive_type(KernelGlobals *kg, const ShaderD
 
 ccl_device_inline AttributeDescriptor attribute_not_found()
 {
-	const AttributeDescriptor desc = {ATTR_ELEMENT_NONE, (NodeAttributeType)0, ATTR_STD_NOT_FOUND};
+	const AttributeDescriptor desc = {ATTR_ELEMENT_NONE, (NodeAttributeType)0, 0, ATTR_STD_NOT_FOUND};
 	return desc;
 }
 
@@ -79,7 +79,8 @@ ccl_device_inline AttributeDescriptor find_attribute(KernelGlobals *kg, const Sh
 
 	/* return result */
 	desc.offset = (attr_map.y == ATTR_ELEMENT_NONE) ? (int)ATTR_STD_NOT_FOUND : (int)attr_map.z;
-	desc.type = (NodeAttributeType)attr_map.w;
+	desc.type = (NodeAttributeType)(attr_map.w & 0xff);
+	desc.flags = (AttributeFlag)(attr_map.w >> 8);
 
 	return desc;
 }