Pipe command cap G3 curves


I want to create a series of handrails using the command pipe. I have generated G3 curves parallel to ramps that I am trying to use to create the pipes (see attached drawing). I have used the three types of capping (none, flat and rounded) but none of them generates an acceptable finish when rendering, the ‘flat’ option generates a square cap that looks awkward on a round pipe and the other two options have awkward endings far from a neat pipe ending. I have tried generating the pipes in Grasshopper and had no luck. Boolean doesn’t work either. The straight vertical railings generate satisfactory pipes so I suspect there is some issue with the G3 curves. I have turned two curves into G1 curves and it has produced acceptable results (first pair of railings top left) although I really wanted curved pipes. However when I have tried to do the same thing in two more G3 curves it has produced very strange endings on ‘t’ form (second pair of railings from top left). So I really don’t know where the problem lies and I would really appreciate some help. I have spent all day working out where the problem was with no success and I really need to finish the drawing.

(John Brock) #2

Can you please post part of a file that shows this problem?
It sounds like you have a poorly fitting display mesh and are confused thinking the fast meshes are some indication of smoothness.

Try switching your Options - Mesh from Jagged to Smoother. It won’t be perfect but if I’m right, it will be better. If that’s the case, you can use the Custom Mesh option and tweak these “eye-candy” settings The cleaner and better fitting the mesh is, the slower the display response will be. It’s a trade off for a pretty monitor display. None of these mesh settings has anything whatsoever to do with the NURBS surfaces and their accuracy.


Hi John
Thanks for your quick response.
I thought I had already uploaded the file but I don’t think it is necessary now because I have followed your instructions and yes the rendering shows a good smooth flat capped pipe.
Thanks again!

(John Brock) #4

Here’s a link to more details on the subject of meshes in Rhino. You’re primed now so it will make sense.