Hi guys, I wanted to share with you a custom library I made, that was very helpful on my project. It implements the basic constructive operations on meshes, like union, intersection, subtraction etc. In 3 words, it's called "constructive solid geometry". The library is an adaptation from csg.js (http://evanw.github.com/csg.js) for BabylonJS meshes. You will find this lib useful if you meet the need to dynamically build your own geometry with basic primitives. For instance you can carve cylindric holes in bigger cylinders to create pipes (wink wink to all old-school Half-Life mappers down there ). Anyhow, you can find the repository over here : https://github.com/CraigFeldspar/BabylonCSG. I'm still testing it, so feel free to signal any bug you would find.. Cheers ! Feldspar.