Surface edges are displayed wrong in rhino viewport

Continuing the discussion from Objects are displayed wrong in rhino viewport:

My display went wrong also.
The wireframe mode is ok but shaded or rendered are not. The shaded mode settings are set to default. Here is a picture in shaded mode:


If I export this object (block) and open the new file, it displays well:

If I draw fresh new objects, the problem remains;

I have tried without success RefreshShade and ClearAllMeshes.

Hi Alan,

You might want to try the solution proposed in this topic:

HTH
-Willem

Thanks Willem. Playing with the testZBiasFactor (increasing or decreasing) arrange the display.

Now I can clearly see that, when zooming, I have a cutting problem too !