Public Release: 

New computational method introduced for lighting in computer graphics

Shedding light in real time

Association for Computing Machinery

BANGKOK, Thailand--In films, video games, virtual reality environments and other computer graphics arenas, lighting is key in achieving accurate depictions of our physical world. Computing lighting that looks real remains complex and inefficient, as the necessary consideration of all possible paths light can take remains too costly to be performed for every pixel in real-time.

A pair of computer scientists at Aalto University in Otaniemi, Finland, with expertise in video game development and lighting simulation algorithms, has developed a new computational method to address this key challenge. Created by Ari Silvennoinen, a PhD candidate in computer science and Jaakko Lehtinen, associate professor of computer science, the novel method enables real-time lighting simulations that are much faster and more accurate than existing methods. They focus on computing realistic indirect illumination from dynamic light sources on mostly static scenes, and demonstrate the accuracy of their algorithm on several scenes where the illumination in the environment consists of complicated patterns of light and shadow.

Silvennoinen and Lehtinen, who are also both research scientists at Remedy Entertainment and NVIDIA, respectively, will present their research at SIGGRAPH Asia 2017 in Bangkok, 27 November to 30 November. The annual conference and exhibition showcases the world's leading professionals, academics and creative minds at the forefront of computer graphics and interactive techniques.

"Real-time dynamic global illumination remains a big challenge in the field. The challenge stems from the fact that, given a scene, any two points in the scene could be in interaction by participating in the light transport from one another," explained Silvennoinen. "The number of these interactions grows very rapidly. For example, with just 1,000 points, we have potentially 1,000,000 interactions."

The key novel contribution is a method that accurately computes indirect illumination using information only from a very sparse set of "radiance probes"--samples that capture scene illumination at a single point - allowing real-time operation in 3D scenes of complexity on par with modern games.

"The quality of the results, in particular the indirect shadows, is very high due to the accurate way we handle visibility between senders and receivers," said Silvennoinen. "Our method makes high-quality indirect illumination, the Holy Grail in real-time computer graphics, practically viable."

In the study, the researchers demonstrate their method on architectural illustrations, accurately showcasing how light through a window moves through a living room over the course of time, for instance, or passes through shadowy columns of a dimly lit palace.

In addition to its direct application to game graphics, the researchers envision this method to enable architects and their clients to see how their design works with dynamic illumination. Also, future work could allow lighting designers to have immediate feedback while placing virtual light sources in computationally restricted environments like virtual reality or augmented reality.

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About SIGGRAPH Asia 2017

The 10th ACM SIGGRAPH Conference and Exhibition on Computer Graphics and Interactive Techniques in Asia will take place in Bangkok, Thailand at the at the Bangkok International Trade and Exhibition Centre (BITEC) from 27 - 30 November 2017. The annual event held in Asia attracts the most respected technical and creative people from all over the world who are excited by research, science, art, animation, gaming, interactivity, education and emerging technologies. The four-day SIGGRAPH Asia 2017 conference includes a diverse range of juried programs, such as the Art Gallery, Computer Animation Festival, Courses, Emerging Technologies, Posters, Symposium on Education, Symposium on Mobile Graphics and Interactive Applications, Symposium on Visualization, Technical Briefs, Technical Papers, VR Showcase and Workshops. A three-day exhibition held from 28 - 30 November 2017 will offer a business platform for industry players to market their innovative products and services to the computer graphics and interactive techniques professionals and enthusiasts from Asia and beyond.

About ACM SIGGRAPH

The Association of Computing Machinery's Special Interest Group on Computer Graphics and Interactive Techniques (ACM SIGGRAPH) sponsors SIGGRAPH Asia 2017. Founded in 1947, ACM is an educational and scientific society uniting the world's computing educators, researchers, and professionals to inspire dialogue, share resources, and address the field's challenges. ACM strengthens the profession's collective voice through strong leadership, promotion of the highest standards, and recognition of technical excellence. The ACM SIGGRAPH deals with all aspects of graphical user/computer communication and manipulation: hardware, languages, data structure, methodology, and applications

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