Unity Grass High Definition Render Pipeline

A high-performance grass rendering utility for Unity's HDRP.

In this side project, I aimed to create a grass shader that can be used over a very large area while still maintaining high visual fidelity by utilizing all the features available in Unity's High Definition Render Pipeline. All of this while ensuring high performance (60+ fps) on high and mid-range hardware and playable performance (30+ fps) on low-end hardware.

Visuals

Render distance and density

Grass.mp4

Lighting

GrassLight.mp4

Currently implemented features

• Rendering of tens of millions of individual grass blades
• High graphical fidelity by utilizing the light loop system of the HDRP, enabling this shader to have accurate lighting on each individual grass blade.
• LOD system controlling the density and mesh LOD of the grass to maintain high performance.

Planned Features

• Grass collision, enabling each grass blade to be affected by physical objects.
• Modification of the individual properties of grass blades (color, length, rigidity...) using multiple textures.
• General performance and API improvements.

Usage

This repository currently contains no code as it is still a work in progress, and I plan on potentially using this grass in one of my games. If this game is released or canceled, I will then make the code of this project publicly available, and you will be able to use it as a learning resource.