minetest-mods/pipeworks

This mod uses nodeboxes to supply a complete set of 3D pipes and tubes, 
along devices that work with them.

See https://gitlab.com/VanessaE/pipeworks/wikis/ for detailed information about usage of this mod.

Unlike the previous version of this mod, these pipes are rounded, and when 
placed, they'll automatically join together as needed.  Pipes can go vertically 
or horizontally, and there are enough nodes defined to allow for all possible 
connections.  Valves and pumps can only be placed horizontally, and will 
automatically rotate and join with neighboring pipes as objects are added, as 
well as joining with each other under certain circumstances.

Pipes come in two variants: one type bears one or more dark windows on each 
pipe, suggesting they're empty, while the other type bears green-tinted 
windows, as if full (the two colors should also be easy to select if you want 
to change them in a paint program).  These windows only appear on straight 
lengths and on certain junctions.

This mod is a work in progress.

Please note that owing to the nature of this mod, I have opted to use 64px 
textures.  Anything less just looks terrible.