A few weeks ago, I had the pleasure of interviewing Chris Jurney, Senior AI Programmer on Dawn of War 2. The interview took place online in front of a virtual audience in AiGameDev.com’s new members area. Chris shared his thoughts and experiences for over an hour, and covered many fascinating topics around real-time strategy AI, path-finding in dynamic worlds, squad movement, vehicle turns, etc.
Below are two excerpts of the interview where Chris talks about applying and extending the AI system built for the highly acclaimed Company of Heroes game to the upcoming Dawn of War 2.
Chris Jurney is a Senior Programmer at Relic Entertainment, working on the AI for Dawn of War II. He previously wrote the path-finding system for Company of Heroes, and worked at Kaos Studios also as a Senior Programmer.
Audio / Video Recording
Alex J. Champandard: Were there any particular aspects to the pathfinding that turned out to be much better than you were expecting when you started? For example, the complexity of the maintaining of the higher level sector might have been something where you didn’t foresee the complexity of. On the other side of the scale did you have anything that worked out much better than you thought it would?
Chris Jurney: Yes, a couple of things, I guess. One, the use of multiple copies of the map to support different pass types. In the Company of Heroes engine and in Dawn of War the designers can actually add new movement capabilities to the units based entirely on the data. So if they decide they want to add a burrowing unit then all they have to do is to add the burrowing type to the data and specify which buildings and terrain features block burrowing units or not. And then all of a sudden the pathfinding supports burrowing. So that was really handy and that propagates through all the maps, the sector maps and the grids and everything.
I was also really happy with the formations system worked out really well. We worked really hard to make the group movement in Company of Heroes look non-robotic. We were observing our previous RTSs and a lot of other RTSs on the market. When you issue a move order to units or whenever they’re moving across the terrain, they don’t really look like real living things. They look like little blips on a radar, with legs spinning under them. We spent a lot of time getting that motion to be organic. I thought that worked out really well.
Alex J. Champandard So here is your chance to sell the game to us! What features in Dawn of War 2 in the AI are you particularly fond of?
Chris Jurney: I think my favorite part is how the squad plans evolve to handle the universe of Dawn of War. One of the tough things about this game was, that there is vastly more unit types. So in Company of Heroes, when we make one animation, it applies to every character in the game. All humans run the same and all our characters are human in that game. Whereas in Dawn of War all the characters… the characters are vastly different. Scales, even when they’re bipeds, some of them have more legs than others, more arms. So it made it… it was a bit limiting in the range of animation that we could get.
But on the upside, and the thing that I think came out really great… is that the units have drastically wider capabilities. For example the Eldar have the ability to teleport. So that plays into how they react in a squad combat situation. I they’re going to move up to cover, they’re not going to run there. They’ve got a teleport pack on. That plays out really interestingly. I think it looks super cool when instead of doing leapfrogging as a walk they’ll teleport from cover to cover until they can finally kill you the way they want. And the same goes… some of our units have flight. Space marines have jetpacks on. If they’re going to run up to you in combat, they’re not going to run, right? They’re going to charge in, use their jetpacks. They might bounce from cover to cover on the way in. So, all those really extreme unit types combined with the squad AI system make for a lot of fun.
If you have any thoughts or comments about this interview, feel free to post them below!