BUG? The material preview icon will not render the actual colour

Check the videos below. When I set RGB colour 0, 111, 255, Rhino will change the preview icon in the materials list to a pitch black. As long as I can see, that issue only happens with this particular colour. :slight_smile: The one way to force Rhino render the material icon properly with the desired colour is to switch to the HSV wheel with visible sliders and manually change some of the numbers and then revert to the original number.
I can see that the preview icon renders at real-time, so maybe that blacked out icon situation is related to the real-time rendering in some way? The icon updates properly if I set it to “Sphere”, “Cube” and everything else except “Scene”. It also works if I set a different size for the preview icons. :slight_smile:

I also attach a portion of the scene so that you can try whether the material will behave in the same way in your Rhino 7.
No icon preview.3dm (44.5 KB)

Looks like you have a cached thumbnail from a failed preview render. You should update the thumbnail - try tumbling the preview.

Sorry, English is not my native language and I can’t understand what is “tumbling the preview”. :slight_smile:
I tried to update all previews, but the icon remains black. I tried to swap the position of the icon, as well to switch to other sizes. They actually render the icon properly in blue, but once I switch back to the small size, it goes black again.

Edit: I found a solution. Moving the slider for “Reflectivity” from 40 to 39 and then back to 40 finally triggered an update of the icon. :slight_smile:

Tumbling the preview means right-click drag in the thumbnail. That gives you the ability to move around the preview geometry.

Funny. :slight_smile: But now it’s oriented in a different angle. Is there a way to reset to the default position of the preview?