Session Title Console quality lighting on mobiles

Session Type Experience Report

Duration 45 minutes

Speaker(s) Matt Wash (Geomerics)

Matt Wash was awarded a scholarship at Goldsmiths, University of London where he specialised in graphics programming. After graduating with distinction Matt joined Cambridge-based lighting middleware company, Geomerics, where he was responsible for porting their real-time radiosity technology to mobile platforms. He then went on to create “Enlighten Palace”, an application demonstrating console-quality graphics running on iOS and Android devices, which was showcased by the leading mobile GPU, manufactures at both Mobile World Congress and GDC 2012.

Session Description

Not that long ago the phrase, "mobile graphics", was a short hand way of implying 2D sprites or very simple 3D rendering. A lot has changed in a few short years. Good looking 3D games, including ports of (older) console titles, are high in the charts and people now bravely talk of "console quality graphics" on mobile. One litmus test for graphical capability is lighting. Quality of lighting is one of the main graphical differentiators of games and modern consoles are capable of rendering scenes with hundreds of direct lights together with real time bounce lighting.

In this talk we discuss our experiences of porting Geomerics real time dynamic lighting technology, Enlighten, to a variety of iOS and Android devices. We show the GPU feature requirements and associated performance figures for a scene with a real time time-of-day lighting setup. We show how both the CPU and GPU can be utilised to render the final result, and the optimisations and approximations we employ to achieve real time rendering rates.

The cost and availability of memory bandwidth is one of the most significant differences between desktop and mobile GPU architectures. We discuss what impact this has on rendering with dynamic lights, and how mobile lighting must be adapted to suit the limitations of the platform. We look at this on current devices and speculate on how we expect this to change in the future.