I need to run an A* search through a hexagonal grid. However, I have one nasty constraint: my vehicle can only turn so sharp. It has a specified minimum turn radius. I can't quite see how to translate this constraint into something I can use with each cell expansion to determine if a neighbor is viable or not. My grid cells are significantly smaller than the minimum turn radius.
I have an initial angle and location of the vehicle; it seems I need to keep a current angle with each cell. With that in mind, I'm not quite sure when I need to reset reference point. It seems that I cannot do that every cell or I will only go in a straight line.
I can translate that turn radius into a polygon (with several hundred sides) where each side length is the distance between my grid cells. I'm not sure how to use this, though.