@Vaillancourt Hmm, I don't like the idea of completely asynchronous nodes... They can't be paused when the game is paused, and they run out of sync with the game loop, making things non-deterministic.

@SethBattin It may not be a good "question", but several people have found the information useful, and judging by the number of jsperf revisions, there is still interest in the topic.

Yeah, it would be faster, but the trouble is, I have 16 light levels, and I am considering going up because the difference from one tile to the next is still rather noticable. That would mean increasing the memory consumption by 16x! I guess I could give this technique a try, it just feels like it wouldn't be fast enough.