Open Collections

Abstract

I present a simple method to render fields of grass, animated in the wind, in real-time. The technique employs vertex shaders to render displacement maps with Russian-doll style transparent shells. Animation is achieved by translating the surface according to a local wind vector while preserving the length of the blades of grass. Lighting is also done in a vertex shader, with point light sources, accounting for the anisotropic nature of grass, self-shadowing and attenuation. This technique achieves convincing results on current consumer graphics hardware and can be applied to other similar surfaces such as hair and fur.