GPU Pro 6

3

III

Volumetric Fog and Lighting

Bartlomiej Wro´nski

3.1 Introduction

This chapter presents volumetric fog, a technique developed at Ubisoft Montreal

for Microsoft Xbox One, Sony Playstation 4, and PCs and used in Assassin’s

Creed 4: Black Flag. We propose a novel, real-time, analytical model for calcu-

lating various atmospheric phenomena. We address the problem of unifying and

calculating in a coherent and optimal way various atmospheric effects related to

atmospheric scattering, such as

• fog with varying participating media density,

• smoke and haze,

• crepuscular rays or light shafts,

• volumetric lighting and shadows.

This chapter provides a brief