Open worlds are proliferating in gaming, but it isn’t easy to do them right. Chip design company ARM is helping developers out with Enlighten, a middleware tool that makes it easier to create open worlds with outstanding 3D graphics and lighting effects.

Enlighten is part of a movement in animation for “global illumination,” or creating light sources such as the sun or reflective surfaces that accurately capture the way that light behaves. Enlighten halves the performance cost for making lighting more realistic, and the result is far more realistic scenes in video game worlds.

That’s important because nine out of the top 10 video games were open worlds last year, according to the NPD Group. ARM and its Geomerics division are demonstrating the new Enlighten middleware at the Game Developers Conference (GDC) this week. Among the examples: Scenes that would have darkened surfaces are now completely lit since the imagery includes both bright and dark regions at the same time.

Chris Porthouse, the vice president of gaming at ARM and the head of the Geomerics and Enlighten businesses, said in an interview that open worlds — like Skyrim, a fantasy world where a player could roam across many square miles of virtual landscapes — have gathered momentum in high-end console and PC markets.

“Developers are delivering even larger worlds with better lighting effects,” he said. “With Enlighten, we can create more vertical spaces and accurately capture the lighting and shadows as the light bounces around.”

Ninja Theory, the U.K. developer of the upcoming game Hellblade, will demo the new Enlighten technology at GDC. Hellblade has a 25-square kilometer world full of vertical spaces such as gorges, forests, and beaches.

Enlighten captures the way that light shines from the sun to a surface, like a cliff, and then bounces off that cliff to other parts of a scene. In the picture at top, the side of the smaller rock would be covered in shadow, but with Enlighten, all of the details of the rock are captured because of the way the light bounces off the cliff.

“The result is a gorgeous scene,” Porthouse said.

The Witcher 3, one of last year’s top titles, covered 136 square kilometers, compared to 39 square kilometers for Skyrim in 2011. Creating the terrain for that much space is a huge challenge for 3D graphics artists.

“We split those scenes into smaller areas and solve the calculations at lower resolutions,” Porthouse said. “The result is a 50 percent improvement in performance.”

The alternative to using Enlighten is to “prebake” scenes, where the lighting is created manually. But it doesn’t work in a dynamic way, like when you are moving around in a scene, so it doesn’t look realistic.

Companies using Enlighten range from Electronic Arts to Capcom.

ARM's Enlighten creates better lighting effects in games.

Above: ARM’s Enlighten creates better lighting effects in games.

Image Credit: ARM