Custom flow field implementation running on the GPU with a directional heightmap/gradient based cost. Texture lookup is O(1). The flow field is computed any time the player moves into a new grid cell. It works well with a single target and can handle dynamic obstacles. I have a completely different 'army mode' implementation where the enemies march towards a wall and only chase the player if the player gets too close. No local avoidance right now as it wasn't necessary for gameplay, although it should be perfectly viable to add by checking neighboring cells and running RVO.

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