blender: Add a few more remarks

Ideally someone more familiar with Blender would be able to point out a
bunch of weirdness in my plugin implementation in 5 minutes. I
constantly feel like I'm doing things the wrong way, and no amount of
browsing the documentation or looking at how Cycles does things has
helped with that.
Cycles mostly just passes the Blender datastructures to the C++ side,
and deals with it there, and I couldn't find many examples of actually
fully using this bpy.types.RenderEngine to integrate a 3rd party
renderer, so this has mostly been (slow) trial and error to get here.
I feel like I've gotten 80% of the way there, but I'm really stuck on
the last 20%

bindings/blender_init.py

@@ -384,6 +384,9 @@ def partial_update_mesh(self, update):
 		mesh = update.id
 		print("Mesh {} was updated".format(mesh.name))
 		# For now, we only handle transforms.
+		# I find it frustrating that the only way to inspect these types is by
+		# dumping them at runtime. It's a really slow way to explore an API.
+		# Surely there is a better way?
 		if update.is_updated_transform:
 			# FIXME: How do I get the actual instance index from Blender?
 			# Just grabbing the first one for now.
@@ -451,7 +454,7 @@ def view_update(self, context, depsgraph):
 			self.cr_renderer.start_interactive()
 
 	def display_bitmap(self, bm):
-		# Get float array from libc-ray
+		# Get float array from libc-ray containing the raw render buffer, and then build a render result with it
 		print("Grabbing float array from lib")
 		start_first = time.time()
 		float_count = bm.width * bm.height * bm.stride