Pathfinding just like those clever humans..

This paper discusses the use of empirical cost-surfaces derived from substantial amounts of player-traced movements in Darkwind, for the purposes of improving A* pathfinding by AI vehicles. My core ideas are that (i) there are a number of subtle factors related to both effectiveness and aesthetic value, which define optimal routes around the terrains, and that (ii) it may not be feasible to deal with these factors algorithmically. I aim to achieve efficient, believable (‘human-like’) routes which navigate terrain features and surface types sensibly, are safe from collision damage and, where possible, enemy fire.

Since Darkwind is a well established online multiplayer game, it provides substantial amounts of empirical evidence about player-chosen routes. The basic premise is that we have thousands of player-controlled cars travelling around the maps every week, so why not let the computer learn the favourite routes taken by humans?

Draft Paper here (pdf, ~3.5MB)

This is all based on ‘votes’ that I have been gathering in the game for the past 12 months or so.

pheromone trails

Chainsaws, Mr. Redfern!

This has to go down as one of the ‘good moments’ in my Darkwind odyssey..

Here’s the background:

A few weeks ago, after much discussion, the Rules Council (RC) and I decided to downgrade the effectiveness of the ‘sniper’ specialism for heavy weapons. This was an attempt to rebalance the over-powerful car cannon and similar weapons. But it caused a lot of trouble, tantrums and players threatening to quit the game, etc. The same nonsense I have seen several times before.

So eventually I lost my cool and reversed the change, making this forum post: “You know what? I’ve had enough of this crap. I’m just gonna revert it. Anyone want any tweaks in future? you can go sing for it.”

Anyway.. there’s a long-term player who goes by the screenname of Rev V, who runs a gang of rampaging post-apocalyptic nuns… and the Good Reverend has been asking for chainsaws in the game for over a year now…

So on Friday evening I logged onto the forums and found a post linking to this:

Chainsaws Mr. Redfern, by Rev V. (mp3 song)

 

So he sung for it.. needless to say, I spent most of the weekend implementing chainsaws in the game ;-)

Love to pull on the ripcord.
Squeeze that trigger hear the engines whine.
Got gas to burn, so Mr. Redfern….
I think chainsaws would be fine!!!!!

We got lasers, but no chainsaws…
As a reverend, I say that’s a sin!
Between you and me, screw the RC!
Do what’s right and put ‘em in!!!!

Bulletholes

I finally got around to implementing bullethole decals that are blended into the vehicle skins in Darkwind whenever they are hit.

The code is just a slight rework of that already used for custom decals; the major thing holding me up on this one was the problem of how to know where in the vehicle’s texture they should be blended. I have been in possession of some experimental ‘3D world to texture co-ordinate’ code since being given it by a developer on Garage Games a few years ago, but never got around to delving into it.

What I ended up doing was much simpler: place the decals into a random position within the region assigned to the vehicle facing (front, rear, left, right, top, bottom) that took the hit. As always, there were several players very generously offering to help out with the legwork of definining the pixel co-ordinates of these facings in the skins of each chassis type. Thanks to Tinker and FireFly who came up with the goods ;-)