Control points/polygon: how to see it through a surface?

is there any way in rhino 5 to show controlpoints/polygon like in image 2 ?



I do not mean by using ghosting or using material transparency.



Hi Daniel, does the CullControlPolygon command do it when turned OFF ? Why not use a transparent shaded material in a dedicated display mode with individual Control Polygon settings, eg. solid lines in different color etc. ?


HI Clement,

thanks for your suggestion, but CullControlPolygon is off for that screenshot.

When using a transparent shader, you see ALL other objects behind the surface.very distracting.
I just want to clearly see all the control polygons/points on the object I am currently editing. also transparent shading takes away surface detail (shading), that is important as visual feedback during surface modelling.


I´ve feared that. Another, rather ugly workaround would be:

  • Use ExtractControlPolygon of your surface
  • select the resulting mesh, run _ExtractWireframe
  • group the resulting lines
  • delete the mesh
  • Select the grouped lines and run _BringToFront
  • Group the lines with your surface
  • Select the result and turn _PointsOn

This way you have a control polygon which is in front regardless of the shademode or transparency. The downside is, you can only window select controlpoints and the gumball will not allign to object anymore.

I guess it would be possible to write a python script which sets up a display conduit which permanently draws a control polygon in the foreground…

+1 for a display mode setting which allows to draw the control polygon of curves and surfaces in front of everything.


Ha! that is a nasty hack indeed, for points to be visible, one would need to run extractPt, too.

anyways, thanks for the input!
I really hope this can be added, it used to work like that… long time ago.

I do see an advantage in being able to tell where the ControlPolygon intersects the rendermesh mesh, (the CP line disappearing), but I’d prefer an option to render maybe a differently coloured ControPolygon if behind the surface, or just an intersection point looking different from the CP.


in fact this problem also shows in this respect:

the top line has editPT turned on: (i use 3 pixel curves in that displaymode)

but even with 1px curves one can see that the line is blocking visibility of the point

Hi Daniel - I’ve encountered this as well - I’ve put it on the pile for the developer to look at.



turn on points for the whole group (the surface and lines) to make all visible… :wink:


Hi Pascal,

thanks, great If you guys can have a look at it!


i got u ! but if they are not point objects, bringToFront has no works on lines but not the lines controlPoints. at least that is what i see here.


RH-26022 is fixed in the latest Service Release Candidate