steering or path finding?

I would have thought that the two go hand-in-hand; use traditional path-finding methods to obtain a list of nodes and then use steering to follow that path in a realistic manner.

I doubt they used steering in early Warcraft games. I've not seen the more recent ones though so I have no idea about those.

Listen to the good mod.

You use pathfinding to generate a list of nodes, then you use stearing to move through those nodes.

How do you do this?

You go and you use forces.
You have a large (and rather strong) force which is pushing the character into a line between any of the nodes.
You also have a smallish force, which is forcing the character forewards.
YOu also have a variable force, which provides repulsion from the obsticals. These should do up quickly as you get really close.

You also have a random force, which slowly changes in direction and slowly changes in intensity. This force should never be enough so that it just packs up and moves in the wrong direction (most of the time), but it should be enouhg so that it won't just stand perfectly in line with the other forces.

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Here's an example of path following using steering (the path is not computed by an algo though, but its pretty easy to figure out how to do it).

If you need more infos on steering, take a look at Craig W. Reynolds' web site...

Hope this helps.

Forces and steering are probably overkill for a strategy game.
I'd simplify by interpolating orientation along the path, making sure each waypoint (each tile if you're doing it tile-based) has a proper orientation (which should be obtained from the current waypoint position, the last waypoint position and the next waypoint position.

er.. dunno if I make myself clear. I'd say this is what Warcraft III uses, but thats just an opinion.

Quote:

Original post by Madster Forces and steering are probably overkill for a strategy game.

When you have 873874 units in a small area pathfinding just simply won't work well (or at all). You might find a nice path from Point A to Point B but you'll be halfway there when a hellfire tank squad blocks your way - what do you do then? If all you have is path finding you'll just wait till the tank is gone and or worse you'll have to computer a new pather which is a real killer. Steering behaviours are really fast to compute and they are easy to write (simple get the vectors between yourself and where you want to go, the closest unit, and some random vector, weight them, then add together ... very simple), and they work wonders where set paths don't. If you have 1 unit walking across a blank map then they're definatly not worth the effort, but in crowded situations they're a life saver, and even if a unit gets stuck he'll still try to find his way out which will look way more realistic that just stopping dead everytime someone gets in his way.

Steering behaviours are good once you have a pathfinding manager.

As your getting your new paths ready (for eg. A bridge got blown up and now you need a new path), you simply use steering behaviours to move towards the point.

Also, paths are very fast: Usually below 100ms (or well below that for small paths) For whole paths (you only need a few nodes in the future, and that is FAST)>

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