It would be awesome if you could stretch items around and use it to sculpt things like terrain
While that would be an awesome feature, I think proper 3D modelling tools like Blender, Vectary, Figuro, and Clara.io are a better fit for sculpting. There’s a reason other 3D game engines like Unity & Unreal Engine don’t attempt this!
Geoff @ TechLeap
Try this SculptGL - A WebGL sculpting app