Starting with Babylon.js v2.1, we introduced decals.
Usually used to add details on meshes (bullets hole, local details, etc...), a decal is a mesh produced from a subset of a previous one with a small offset in order to appear on top of it.
To create a decal, you can call this code:
var newDecal = BABYLON.Mesh.CreateDecal("decal", mesh, decalPosition, normal, decalSize, angle);
This function takes the following parameters:
You can play with a sample here (Try to click on the cat):