Polysurface losing colour

I’ve seen this a few times with larger polysurfaces. It’s best explained by a video:


Notice how the part goes gray when the view is manipulated by rotating, zooming or panning.

Has anyone else seen this?



I haven’t seen this. Can you post the 3dm or send it into tech@mcneel.com? A screenshot of your OpenGL info from Options>View>OpenGL would be good to see as well.

Here is the screenshot. I’ll put the file on OneDrive and send you the link privately (the file is 31Mb zipped). I can’t post it publicly.



I’ve narrowed it down to this:

Losing colour.3dm (284.9 KB)

I’ve discovered that if you explode the polysurface and join the surfaces individually, it behaves correctly. If you explode that, then pre-select and join, the colour problem reappears.

Here is a quick video:


Hope this helps,


Hi Dan, I see that here - thanks. Hm - I see a tiny sliver surface on the end - that seems to be the culprit. There are 6 real surfaces, which work right, then adding the sliver in sends it all south. It seems only to be selectable by selecting the six real surfaces and then Invert. That should be a bad object, I’d think.



Thanks guys, I went to lunch and you’ve got it narrowed down and filed already!

Yes, I see that now. It’s usually the smallest slivers that cause all of the grief!



Hi Dan,
I’ve seen this on large imported meshes too.