Update geom_utils.py

Added notes on room_norm_vector

sound_objects/intern/geom_utils.py

@@ -45,11 +45,20 @@ def room_norm_vector(vec, room_size=1.) -> Vector:
 
     The room is a cube with the camera at its center. We use a chebyshev normalization
     to convert a vector in world or camera space into a vector the represents the projection
-    of that vector onto the room's walls.
+    of that vector onto the room's walls. The Room Vector is the immediate the X, Y and Z 
+    coordinate of the corresponding ADM Block Format source object position.
 
     The Pro Tools/Dolby Atmos workflow I am targeting uses "Room Centric" panner coordinates
     ("cartesian allocentric coordinates" in ADM speak) and this process seems to yield good
     results.
+    
+    I also experimented with using normalized camera frame coordinates from the 
+    bpy_extras.object_utils.world_to_camera_view method and this gives very good results as
+    long as the object is on-screen; coordinates for objects off the screen are unusable.
+    
+    In the future it would be worth exploring wether there's a way to produce ADM 
+    coordinates that are "Screen-accurate" while the object is on-screen, but still gives
+    sensible results when the object is off-screen as well.
     """
     chebyshev = norm(vec, ord=numpy.inf)
     if chebyshev < room_size:
@@ -99,4 +108,4 @@ def speakers_by_min_distance(scene, speakers):
 
 
 def speakers_by_start_time(speaker_objs):
-    return sorted(speaker_objs, key=(lambda spk: speaker_active_time_range(spk).start_frame))
+    return sorted(speaker_objs, key=(lambda spk: speaker_active_time_range(spk).start_frame))