Creating L Systems in Blender Geometry Nodes

L Systems are a mathematical ‘grammar’ to define fractal shapes. They’re great for generating convincing natural shapes like trees and plants. They work by generating a string of characters and defining operations to replace them with more complex strings. Thanks to Blender 4.0’s new repeat zones, we can now simulate this in Geometry nodes!

Hi! I’m sorry to be using this forum as a stack exchange, but it’s been a few days of me struggling with trying to make this work. I’m stuck at the part, where you made the mistake of passing the up vector into the direction socket, so the branching did not end up working correctly. I fixed the mistake and checked it hundreds of times now, but something still seems broken and the “/” and “\” commands are being ignored, as I’m now getting an “unknown socket value” error in the “string equal” node, which makes no sense to me at all. I’d really appreciate a pointer, if you’ve any idea what might be going on! Thank you so much for your work and this video!