PRTT: Precomputed Radiance Transfer Textures

TL;DR

This paper introduces transfer textures for precomputed radiance transfer, enabling high-quality glossy rendering at real-time frame rates by decoupling transfer data from mesh resolution.

Contribution

It presents a novel use of textures for storing transfer data, improving rendering quality and performance for glossy materials in real-time applications.

Findings

Transfer textures achieve comparable or better quality than vertex-based methods.

Decoupling transfer data from mesh resolution enhances rendering flexibility.

Real-time rendering performance is improved with transfer textures.

Abstract

Precomputed Radiance Transfer (PRT) can achieve high quality renders of glossy materials at real-time framerates. PRT involves precomputing a k-dimensional transfer vector of Spherical Harmonic (SH) coefficients at specific points for a scene. Most prior art precomputes transfer at vertices of the mesh and interpolates color for interior points. They require finer mesh tessellations for high quality renderings. In this paper, we explore and present the use of textures for storing transfer. Using transfer textures decouples mesh resolution from transfer storage and sampling which is useful especially for glossy renders. We further demonstrate glossy inter-reflections by precomputing additional textures. We thoroughly discuss practical aspects of transfer textures and analyze their performance in real-time rendering applications. We show equivalent or higher render quality and FPS and demonstrate results on several challenging scenes.