After you see a sequence, you might say, ‘Oh, no — we need to have that character arrive a second sooner. You can have the system ‘re-perform' that sequence in just a few seconds. The actors re-hit their marks. You’re now polishing iterations by watching the entire sequence play back in realtime.”

Unreal Capabilities
Lanning acknowledges that CGI rendered in realtime still has limitations. “Where realtime production is still challenged is that it doesn't do anti-aliasing that well. No one has really nailed that down. So instead, as in the early days of computer graphics when they didn't have reasonable anti-aliasing algorithms — like on The Last Starfighter (1984) — they rendered at 8K. That's kind of like where the realtime world is. But there are images that are playing at greater-than-HD quality in realtime.

Unreal Engine 3 is being utilized on such big games as Star Wars: Knights of the Old Republic. © LucasArts Ent.

A technology that Lanning sees as emblematic of realtime production’s future is Epic Game's Unreal Engine 3, a tool for creating realtime interactive worlds for the newest generation of consoles and PCs. Unreal turned heads at E3 this year, and Epic partnered with Alias and others to present Unreal classes at SIGGRAPH, too. The Unreal 3 engine has already been embraced by the creators of the next Star Wars and Men of Valor games.

Lanning believes ”Unreal is, hands-down, the best realtime rendering we’ve ever seen. It looks like you're walking through streets of old Venice. What it's doing is normal mapping that allows a 7,000-polygon character to actually look almost identical to a 5 million-polygon character. The thing that the hardware manufacturers in the videogame business don't quite understand yet is that mapping and memory is more important than polygons — they think that polygons are more important than texture mapping, and they're wrong. The people in this medium who are artistic understand that mapping can create the illusion of billions more polygons.”

The Efficiency Factor
Lanning thinks it’s just a matter of time before technology such as this is used to generate linear as well as interactive “game CG” — for reasons of efficiency, if nothing else. “The world of pre-rendered cinematics in videogames will keep getting smaller, while the world of cinematics created with realtime game engines will get bigger. Eventually, in games we'll probably be looking at virtually all in-engine — whether it's a cinematic that you can interact with, or an interactive situation that feels much more cinematic.”

In the past, our games had, let’s say, 24 minutes of computer animation. Well, it is too expensive today to do that with pre-rendered. So we're only using pre-rendered CG in areas where real-time can’t achieve what we want — primarily in the emotional arc of the hero character. In Stranger, we broke that down to about six different clips — the opening, the ending and a few in between. We thought, ‘What if the game engine was capable of delivering parts of the story that we used to do in pre-rendered?’”

While Stranger is still a work-in-progress, and the answer to this question is still evolving, Lanning is pleased with what has been achieved thus far with realtime techniques. "We used two completely different sets of assets — ones that we would use for pre-rendered that had greater polygon counts, greater facial expression capability, more bones in the body, all that. And another set of assets used for realtime that didn't have as many bones, not as much facial capability and not as many high-resolution texture maps. We're trying to run 50 of those characters in a world at one time. So we said, `Let's try some experiments. On some of the ones that we want pre-rendered, let's bring in the set that was built for the game.' It's all Maya format, so we could bring that in and we wouldn't have to build a second set of assets, like we've always done in the past. That worked out amazingly well. So we thought, `Let's bring the characters in and do the same thing.' We were able to think of the shots in a very pre-rendered way, but we brought in the realtime assets that were built for the game and it worked just fine.

The Bigger Picture
In the wider world of linear CG production, the impetus might not yet be there to embrace more realtime strategies. The time-intensive process of software rendering remains feasible for many studios, especially those that are able to throw greater numbers of inexpensive processors at number-crunching challenges. Lanning observes, “The pre-rendered film world has not been very concerned about efficiency. You can tell that by the speed of Maya and RenderMan — if something renders in a ‘reasonable’ amount of time, then it’s fine.