AIPath get future point on path

General Grid graph
1

I’m using a GridGraph with a barebones subclass of AIPath on each AI agent. I subclassed it so I could override the OnPathComplete callback. I have the list of future nodes in the path, but I’m not sure what the best approach is to get a roughly estimated position x seconds in the future, since there can be a different length of time and distance between each subsequent node in the path list.

The context is basically this: I have a separate system that handles influence mapping on a ~(1-3)sec tick between updates for any given AI agent, provide that agent is on a different tile than it was the last tick. If an AI agent is moving, I want it to process half of the influence at its current position, and the other half at its future position, so the result is an interpolation. To do this, I need to be able to estimate an agent’s position x seconds in the future. Since the path is already calculated for pathfinding anyway, I figured that was the best thing to use for the future position estimate.

The only way I can think of to do this is to start iterating through the path from the start, read the distance and remainingDistance floats at each step and stop at a node where distance is close enough to some estimatedDistance value that is just the current speed * predictAheadTime, or the last node in the array if remainingDistance < estimatedDistance (which it shouldn’t ever actually be, since the predict ahead time will probably almost always be under 5sec at most, 1 sec or less will be more common).

Is there an easier/faster way to do this than my above idea?

Thanks @aron_granberg !

2

Hi

You could do something like this:

var buffer = new List<Vector3>();
ai.GetRemainingPath(buffer, out bool stale);
var interpolator = new PathInterpolator();
interpolator.SetPath(buffer);
// Set the interpolator's distance from the start of the path, this will change interpolator.position
// to the point corresponding to that distance from the agent's position.
interpolator.distance = desired distance ahead of the agent;
// Draw a line to the point
Debug.DrawLine(ai.position, interpolator.position);