Cycles: Camera frustum space object culling scene simplification

The idea is to give artists a simplier way to control memory usage in such
scenes as grass fields by doing automatic object culling based on whether
object is visible in the frame or not.

This is controlled on per-object level. In order to use this option few steps
are required:

- Enable Simplify in scene settings

- Enable Camera Cull option in the Simplify panel

- Set camera cull margin (measured in relative value to the render resolution)
  This setting is used to avoid possible flickering caused by changes in shadow
  which are cast by objects outside of the frame.

- Enable Camera Cull for objects which are desired to be culled
  (object culling option could be found in Option panel in object buttons).

There is still room for improvements, but this worked quite well during
Gooseberry open movie project, so think it's useful feature even in it's current
non-ideal state.

1 files changed, 10 insertions, 2 deletions

diff --git a/intern/cycles/blender/blender_sync.h b/intern/cycles/blender/blender_sync.h
index 89d93e19e9f..b8bd14c0f71 100644
--- a/intern/cycles/blender/blender_sync.h
+++ b/intern/cycles/blender/blender_sync.h
@@ -85,8 +85,16 @@ private:
 	void sync_nodes(Shader *shader, BL::ShaderNodeTree b_ntree);
 	Mesh *sync_mesh(BL::Object b_ob, bool object_updated, bool hide_tris);
 	void sync_curves(Mesh *mesh, BL::Mesh b_mesh, BL::Object b_ob, bool motion, int time_index = 0);
-	Object *sync_object(BL::Object b_parent, int persistent_id[OBJECT_PERSISTENT_ID_SIZE], BL::DupliObject b_dupli_ob,
-	                                 Transform& tfm, uint layer_flag, float motion_time, bool hide_tris, bool *use_portal);
+	Object *sync_object(BL::Object b_parent,
+	                    int persistent_id[OBJECT_PERSISTENT_ID_SIZE],
+	                    BL::DupliObject b_dupli_ob,
+	                    Transform& tfm,
+	                    uint layer_flag,
+	                    float motion_time,
+	                    bool hide_tris,
+	                    bool use_camera_cull,
+	                    float camera_cull_margin,
+	                    bool *use_portal);
 	void sync_light(BL::Object b_parent, int persistent_id[OBJECT_PERSISTENT_ID_SIZE], BL::Object b_ob, Transform& tfm, bool *use_portal);
 	void sync_background_light(bool use_portal);
 	void sync_mesh_motion(BL::Object b_ob, Object *object, float motion_time);