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, 33 insertions, 0 deletions

diff --git a/intern/cycles/render/object.cpp b/intern/cycles/render/object.cpp
index 5dbe2e4d6a1..eeb44f46685 100644
--- a/intern/cycles/render/object.cpp
+++ b/intern/cycles/render/object.cpp
@@ -29,6 +29,8 @@
 #include "util_progress.h"
 #include "util_vector.h"
 
+#include "subd_patch_table.h"
+
 CCL_NAMESPACE_BEGIN
 
 /* Object */
@@ -607,6 +609,37 @@ void ObjectManager::device_update_flags(Device *device,
 	device->tex_alloc("__object_flag", dscene->object_flag);
 }
 
+void ObjectManager::device_update_patch_map_offsets(Device *device, DeviceScene *dscene, Scene *scene)
+{
+	uint4* objects = (uint4*)dscene->objects.get_data();
+
+	bool update = false;
+
+	int object_index = 0;
+	foreach(Object *object, scene->objects) {
+		int offset = object_index*OBJECT_SIZE + 11;
+
+		Mesh* mesh = object->mesh;
+
+		if(mesh->patch_table) {
+			uint patch_map_offset = 2*(mesh->patch_table_offset + mesh->patch_table->total_size() -
+			                           mesh->patch_table->num_nodes * PATCH_NODE_SIZE) - mesh->patch_offset;
+
+			if(objects[offset].x != patch_map_offset) {
+				objects[offset].x = patch_map_offset;
+				update = true;
+			}
+		}
+
+		object_index++;
+	}
+
+	if(update) {
+		device->tex_free(dscene->objects);
+		device->tex_alloc("__objects", dscene->objects);
+	}
+}
+
 void ObjectManager::device_free(Device *device, DeviceScene *dscene)
 {
 	device->tex_free(dscene->objects);