Region map tuning

Some more region map tuning for performance and to support a ui that interacts with multiple variables.

After trying a bunch of low level techniques and them all becoming quite messy, I think the better way to attack it is controlling the boolean logic at a higher level since it's coming from the UI anyway.  So once we have the input, just make (or updated) a binary variable that is displayed with a new colormap (trans & not trans).  This should be able to be done with just a few calls.