Rendering glitch when using tool Sweep 1 rail and revolve

I have the evaluation of Rhino version 5.5.3 for mac.

I am trying to run a profile along a curve, and have done this by using the sweep tool and the revolve tool, both worked, until I tried to cap it. For some reason the rendering goes pixelated and makes it look like there is an error with the shape, in shaded and render mode. However there are no bad objects and the profile is a closed curve. I have check to see if increasing my render setting to high quality makes a difference but it does not.
A colleague of mine opened my file on his rhino mac and saw the same outcome. However when he duplicated my original profile and curve and revolved it, it worked and looked clean.

Puzzled as to why this is happening,
Any theories much appreciated.


Hello @grace

Mine is only a hypothesis, but perhaps the curve for the sweep is not planar.
Try using the “ProjectToCPlane” command in the top view and try the Sweep again.