I'd like to use equilateral sqaures as my navgiation data. It doesn't matter if it doesn't cover the whole scene. I just want some source code that can help me implement that correctly Any good links? And also, when implementing such thingy, if there are t-junctions between the geometries, isn't that not possible for AStar to work correctly, is it? Thanks Jack

A* is just a graph search algorithm; it doesn't care about things like T-junctions. If you can map your search space to graph nodes and edges in a reasonable way, then A* can search it.

As for the rest of your question, I can't quite visualize what you're asking. Any possibility you could post an example image?