Ghosted View - Redraw flickering

Hello,

I have stumbled onto a problem that is causing a few headaches.

I am developing a plug-in that requires some computational control over the color of breps. I have found that when models are displayed as ghosted breps the edges of these breps flicker whenever the screen is redrawn and coincident edges exist.

This happens based on the orientation of a view / camera location. In some orientations redraws cause flickering while in other orientations the very same objects do not flicker.

The flickering only happens with:

  • Brep objects with coincident edges (visible when different color edges touch).
  • Ghosted views
  • Regardless of display conduit use (ie. when Pre / Post draw is enabled or not).
  • Regardless of an object being edited/altered between redraws.

Is there anything that I can do to prevent this from occurring?

Update:

With further experimentation it seems that this flickering might be an inherent result of any Ghosted view.

For example as a test I built a new and different object and dragged it across the screen. During the drag other brep objects, as described in the above post, flicker. This flickering seems to happen even when no plugins are initialized.

I understand that the development team is busy but if possible it would be nice for this flicker to be addressed in a future release.

If you run just Rhino (and not your plug-in), does the screen flicker in Ghosted mode?

What kind of video card do you have? Can you post a screen capture of Rhino’s OpenGL page in Options?

Dale,

Yes the flicker is in native rhino with no plugins running.

The screen snap shows what I believe are all default values - as well as card details. It’s an older machine (2011) but still quite useful.

Maybe it’s time to replace the machine?

Dale,

I’ve performed the same test as previously mentioned (opened rhino - no plugins - have a model open in ghosted and build a box that I then drag across the screen to watch for flicker) on another computer. I find no flicker.

That said - a quick question for you:

The plugin that I am developing does require a viewport redraw and the redraw does cause a flicker when in ghosted views - Is there a known way to prevent this?

The screen capture indicates that the video driver is a bit old - 9-27-2012. So you might consider updating the driver on this system.