Closer to reality: photorealism in computer graphics
Photorealism is the holy grail of computer graphics. In movies, whether artists are recreating tigers and raging oceans for Life of Pi, or building giant monsters and battling robots for Pacific Rim, the goal is to create something that looks real.
Even when realism isn’t the principal aim – as in Despicable Me 2 or Monsters University – the studios are looking for something to take their film to the next visual level, whether that’s through natural textures, realistic fur or sumptuous lighting.
Photorealism is just as important for games. It might not mean much in an artsy independent game or an iPhone time-waster, but for racing games, fantasy adventures and hard-hitting action titles, the more realistic the graphics, the easier it is to immerse the player in the game’s world. Each new hardware generation, GPU and game engine takes us one step further.
Studios are looking for something to take their film to the next visual level, whether that’s through natural textures, realistic fur or sumptuous lighting
Games and movies face two sides of the same problem. The offline computer graphics (CG) used in movies – where scenes are set up then rendered frame by frame – have produced photorealistic effects for more than a decade. However, this approach is slow and expensive, and makes it awkward to tweak scenes or try different styles or angles.
Game developers, on the other hand, must balance their desire for photorealism with the need for interactivity. A high-end PC could produce Pixar-quality graphics, but not at a playable speed.
Both groups need something that can create photorealistic results in real-time. Amazingly, this might be just around the corner.
Tim Sweeney, the brains behind Epic Games’ hugely successful Unreal Engine, told the UK’s Develop conference in July that “we’ll be able to render environments that are absolutely photorealistic within the next ten years”.
At this year’s Game Developers Conference, Epic unveiled a demo for the upcoming Unreal Engine 4, showing movie-quality animation running on a single Nvidia GeForce GTX 680.
Meanwhile, Mark Cerny, PlayStation 4’s architect, told delegates at Develop that “we are at the point in the PlayStation 4 generation where we’ll forget sometimes that we’re looking at CG, rather than captured video”. This doesn’t mean it will be indistinguishable, but “at times we’ll be able to forget”, he said.
Pixar-quality cartoon rendering in real-time is also on its way. In 2012, Unity Technologies revealed The Butterfly Effect, a short film running in real-time in the Unity engine with Nvidia GPUs. Using techniques traditionally reserved for offline rendering, its visual quality is hard to distinguish from the work being produced by Hollywood CG studios.
According to Sean Tracy, US engine business development manager for Crytek, the time for real-time photorealism is now. In February, Crytek launched Crysis 3, and its CryEngine 3 graphics engine is now powering key games for next-generation consoles and more serious simulations.
“We’ve considered our technology able to achieve photorealism for quite some time,” claims Tracy, even if “the distinction of being photoreal or not is mainly subjective, and heavily dependent on the quality and talent of artists working within a particular piece of technology.” He believes CryEngine provides the tools artists need to create photorealistic graphics. The rest is up to them.