Custom Heuristic?

Hi, was wondering if you guys have thought about adding custom heuristics when finding paths?

as an example, with a custom heuristic I could drive the direction of found paths to exclude certain directions. Imagine an enemy following a player. The player wants to move behind the enemy to avoid it, but shouldn't turn around and walk towards the enemy. It should keep moving forward and look for a path that leads back around behind the enemy. With a custom heuristic I could increase the cost of a node based on the current path direction of to that node towards the enemy.

Something like:

Code (CSharp):

1. NavMesh.CalculatePath(playerPos, enemyPos - enemy.forward * 3, areMask, CustomHeuristic);
2.  
3. float CustomHeuristic(Vector3[] cornersSoFar, int cornerIndex, Vector3 sourcePosition, Vector3 targetPosition) {
4.    
5.     Vector3 currentCorner = cornersSoFar[cornerIndex];
6.     Vector3 previousCorner = cornersSoFar[cornerIndex - 1];
7.  
8.     float directionOnEnemy = Vector3.Dot(currentCorner - previousCorner, currentCorner - enemy.position);
9.  
10.     return directionOnEnemy < 0 ? float.PositiveInfinity : (currentCorner - targetPosition).magnitude;
11. }

I'm sure you guys could come up with a better callback, maybe passing in a struct of data instead of all those parameters.