this is a proof of concept of l-system tree/plant generator or a growth simulator using lineRenderer of unity engine.
video demonstration

1. copy scripts to your projects.
2. add a + > Empty gameObject of any name with Lsystem.cs script attached.
3. make a prefab of + > Effects > line.
4. adjust end cap vertices of the prefab if you wish.
5. attach Twig.cs script to the prefab.
6. set Branch parameter of the first added gameObject as the prefab.
7. BUILD && RUN.