Solid cylinders

I have a lot of issues when modifying cylinder shaped solids. Using move face, moveedge, gumball or SolidPts with cylinder shapes often creates bad geometry. Would also be nice to be able to use mergesrf with cylinder shapes as it fails more often then not.

Is that by Rhino’s definition? i.e. does the object get selected when you run the SelBadObjects command?

Unless for very basic transformations in simple shapes, I would expect that using these lead to less than ideal geometry. This workflow has its use but you need to know what you are doing.

Do you ever get in situations where cylindrical surfaces actually get merged when using that command? I don’t.

Yep - especially trimmed cylinders get wonky - and I agree that merging cylindrical faces would be grand - it is on the heap someplace…
It might be good, in general, for primitives to have special points-on that allow better control, I think that is not too far fetched in itself, though I don’t know how that can be handled or maintained once the objects are combined with others- it would be a very different modeling style. Currently with a cylinder made by the Cylinder command, or extruded from a circle, normal points on gets you extrusion-style points, which may be helpful but all that goes away with trimming etc.


Yes most of these cylinders that go all wonky are the ones that are trimmed in some manner.

I thought I merged a trimmed cylinder surface once… maybe I am just dreaming lol.

I only use the move face and mentioned tools with planar surface conditions. If the cylinder surface has been trimmed with a planar surface sometimes it still goes nuts.