Blowing from the West: Simulating Wind in 'Ghost of Tsushima'

In this monologue, Bill Rockenbeck, an engine programmer at Sucker Punch Productions, discusses the techniques used to create windblown motion in the game Ghost of Tsushima. He explains how wind, though invisible, is integrated into various rendered objects like particles, foliage, grass, and cloth through procedural or simulated motion systems. Rockenbeck details the simple wind velocity model, the GPU-based particle system that simulates leaves and environmental interactions, and the use of animated particles for crowd scenes and animals. He also covers the implementation of wind effects on trees and grass, as well as the GPU cloth simulation techniques used for clothing and banners, including methods for collision and layering.