I saw some projects by @freestewart this afternoon that were creating a 'Minecraft' type world and I had a sudden insight as to an easy way to implement a block world that would correctly hide a player behind any blocks. To see this technique used in an actual game, see http://scratch.mit.edu/projects/32836744/ I suspect this could be useful in more types of games than just ones like Minecraft. Perhaps a tank game, or even a simple board game such as chess or scrabble. Or Sokoban (which I think I'll do this weekend) This was very easy to write - it took about 20 minutes. It shouldn't be hard to build it into your own code. I found some suitable Minecraft blocks at http://minecraft.gamepedia.com/Category:Block_renders
lol