Control Points for every Primitive?


am I offered control points for every primitive? Because for a sphere I get them, for a cylinder not …

I’m working with Rhino 5 for Windows on a MacBook Pro via VMWare Fusion.


Well I see some 4 cp for my Cylinder but they don’t allow for surface deforming like with the sphere.

That’s because the cylinder is a “Lightweight Extrusion Object” by default in V5.

You can point-edit a sphere because it’s a single surface, though you should Rebuild it before point-editing because, long story short, the type of surface that gives a precise sphere isn’t very “nice” for point-editing.

Thank You both!

The cylinder is created an a lightweight extrusion object. This is why when you turn on the control points, you can only change the length and orientation of the cylinder. If you would like to deform it, then you need to change it to a polysurface (brep object) first. you can do that using “ConvertExtrusion” command.

Yeah very much, thank You

Raja, your talking about lightweight extrusions. What about in the case of a tube light. Could you turn a tube light into a brep in order to deform it ? Kind of a flex tube light.—Mark

Hi Mark - no there is no provision for that. Though some renderers use objects as light sources, which would accomplish what you are suggesting. Rhino’s renderer only uses lights.