Intro

Inspired by this research paper, I’m building a procedural grass system with physics simulation driven by the GPU Compute Shader in Unity.Each blade of grass is represented as a quadratic Bezier curve, and the tip of the grass blade is affected by natural forces (wind + stiffness + gravity) and collision. I made a slight improvement on top of the Bezier curve representation for the grass, using legendre-gauss solution for better approximation of the arc length (i.e. the grass length).

Demo

This will be the only grass I’ll be touching.

Physics

Culling

I then integrated grass culling thanks to the power of compute shader (for calculating the number of grass and which grass to render) and indirect rendering.

Resources

🔗 Responsive Real-Time Grass Rendering for General 3D Scenes
🔗 Bezier Arc Length

🛠️ Tools used

• C#
• HLSL
• Unity