Creating a solid object from 2 hollow ones

I have a hollow cylinder inside of a tube made from 2 squares of differing sizes that I wrapped an outer surface to. So basically square tube with a round tube inside. How can I combine these 2 components to create a solid were the space between them is filled? The center of the round tube should still be empty.

Thanks for any help.

You can do this in Rhino with polysurfaces. It is generally not recommended though, since the result may not behave as expected in other Rhino operations.

Make the inner and outer polysurfaces. Use the command NonmanifoldMerge selecting both, then run the CreateRegions command on the result. Delete the inner region.

Hi Demetrius - if you mean a kind of tube with different inner and outer shapes, close off the ends of the outer object (Cap command may do it, if the ends are planar) then make the cylinder extend through the end caps. Then BooleanDifference the cylinder from the outer solid.


Thanks for the advice. I think I’m going to need to start from scratch on this project. I basically have 2 squares; say one 2cm and one 3cm. They are 5 cm apart facing each other. I was trying to wrap them to create a rectangular solid shape and then fillet the 5cm corners. I managed to do this but it is not a solid shape and therefore I can’t do any boolean operations on it. I can easily extrude a 3D rectangle but then I am not able to change the sizes of the individual squares unless I explode the shape, but then nothing is connected any more.

If there is a tutorial that I should have watched that covers this, please let me know where I should be studying.

thanks again.

tube.3dm (107.1 KB)

Hi Demetrius - Cap the initial object (Cap command) then FilletEdge to keep it a solid - is that what you have in mind?


That’s extremely basic stuff. You could start with Help -> Learn Rhino.
Or you could explain what is the goal you’re after, it’s not clear what you want.

Hi Pascal,

Thanks for the help. I uploaded the object I’m working with and trying to make solid. I tried to cap it but it give me the standard error; The openings did not have close, planar loops of edges. I’m sure it’s something simple I’m missing here.

Cap, then FilletEdge.


Thanks Marc,

I’ve uploaded the object that I’m working with. I’m trying to turn it into a solid shape so that I can perform boolean operations on it. I’ve tried to cap it but it gives the error. I’ll keep reviewing the Learn Rhino section and watching tutorials. It’s probably something simple I’m missing.

Thanks Pascal,

I guess I was doing it backwards.

Pascal was faster, but here is my file with all the steps in layers…tube_Marc.3dm (416.0 KB)

It’s good for the gene pool.


I really appreciate the help. You guys make it look too easy.