Pipe Builder lets you quickly add pipes into any scene. You can define how many sides you wish to have on the pipes and you can also redefine exactly where the pipe are in 3D scene. All within Unity3D no need to swap back to a 3D editor.

Pipe builder is ideal for placing pipes around other objects, with tools like Insert/ Delete and Extract, it makes it easy to add, remove modify later.

V1.1 : Add a Collision option.

V2.0 : Added Fitting options (Wheel Gate, Leaver gates, and others)
Update UV on the meshes.
Added Bake Lighting options.
More Buttons work with more than one object selected.


For More info see Here