I like to play around with Esri's Computer Generated Architecture (CGA) rule files. And sometimes I actually create something you can look at.
These working rules are published here so others might get inspired on writing (and how to write) their own rules.
A ferris wheel that can easily change diameter, width, cart number, cart color and more parts. Most of them can be changed through handles.
You can change diameter, height, and length of multiple parts of the graduation hat such as the cylinder width and height as well as the cord diameter.
A randomized snow flake. Changing the Seed changes the snow flake's arms.
Inspired by the AbstractTree in London Heathrow this is a very simple and abstract representation of a tree.
I provide all content with absolutely no support or warranty whatsoever. If you file an issue I might be willing to fix bugs or implement features but I refuse any and all guarantees to do so.
The color for the snow flake was taken from http://www.perbang.dk/rgb/C3CBD9/
All available files (CGA-rule files, scene files and (possibly in the future) textures I license under the Apache License, Version 2.0 unless otherwise stated (especially if noted as 3rd party content).