Unity-GPU-LSystem-Generator

Generator of L-System using GPU

Overview

In my final project for CIS565 GPU Programming, our team did an AR procedural generation project that could generate plants using GPU. My work in this project is to implement the L-System Derivation/Interpretation using Unity's Compute Shader and then bring them to the game view.
When I am searching during the project I did not find any L-System implementation that utilize the GPU and compute shader that much, and their runtime is usually slow at large iterations. So I think it would be cool to do a plugin for these who want beautiful and complex L-Systems to their game.
The plugin consists of three functions able to use, the generator which instantiate one specific L-System, manager that can handle a large number of L-System Prefabs, and a simple noise function that could generate a large pile of L-System. Details of how to implement the L-System in Unity and Compute Shader is in AR procedural generation project's Readme, this repo is for instruction!

Generator

• Rules and axiom will be used for context derivation;
• Generations are limited to 6, because current scan method can handle 212644 elements, which is similar to a derived complex string length at iteration 6;
• LSystemDefiner marks which gameobject corresponds to the supposed character( NOTES: the gameobject's name does not have to be F!)
• The length needs to be put as the length of that gameobject in world coordinates, so the GPU will calculate each symbol's position correctly; scale is for moderation in case the user want to have different scales;

Manager

After you create an L-System you like, store it as a prefab and it can be used in Manager.
Manager is a simple object list where you can assign each L-System's Pos/Ori/Scale

Noise

• Noise Plane Size indicates how many tile that the generator will generate L-System Prefabs
• set min range and max range for each prefab(between 0 and 1), and they will have a probability of instantiation of (MaxRange-MinRange)/1

Future TODO

In the current version, I use Unity Instantiate to instantiate these symbols as gameobjects, which is theoretically slower than using DrawMesh or DrawProcedural method. Back when implementing DrawMesh there are a few problems and bugs which stop me from trying this. Giving more time I might try to implement DrawMesh to make it look as the same as using Instantiate, with more efficiency because the use of GPU.