GPU Pro 6

4

II

Real-Time Rendering of

Physically Based Clouds Using

Precomputed Scattering

Egor Yusov

4.1 Introduction

Rendering realistic clouds has always been a desired feature for a variety of appli-

cations, from computer games to flight simulators. Clouds consist of innumerable

tiny water droplets that scatter light. Rendering clouds is challenging because

photons are typically scattered multiple times before they leave the cloud. De-

spite the impressive performance of today’s GPUs, accurately modeling multiple

scattering effects is prohibitively expensive, even for offline renderers. Thus, real-

time methods rely on greatly simplified models.

Using camera-facing ...