Deferred Neighboring Radiance Transfer

Abstract

This paper introduces Deferred Neighboring Radiance Transfer, a new precomputation-based Global Illumination technique. DNRT modifies pre-existing light solutions for static environments enhancing them with reflections and occlusions from dynamic objects. DNRT is particularly well suited for integration with lightprobing techniques as it can exploit light probes data to achieve faster performance. Prior to execution, DNRT computes a set of radiance transfer coefficients. At run-time, working in screen-space, these coefficients are combined with data from the light probes and the G-buffer to generate a new radiance solution. This approach allows DNRT to maintain a low computational cost, with relatively high quality results. DNRT’s computational cost grows linearly with the number of dynamic objects in the environment. For scenarios with a single dynamic object, DNRT is 10 times more efficient than current videogames' industry state of practice methods like SSAO and HBAO. On high-end GPUs DNRT’s time cost is below 0.1 ms per dynamic object.