Rhino 8 Bug: Polysurface Mapping Issue

Oh, my email should have been filled in automatically when you followed that link. tech@mcneel.com is fine too.

@esmith1 Thanks, I’ve received the file. As far as I can tell there are no textures in that model. Did you use bitmap textures on a physically based material or something else?

Hi Jussi,

I don’t do texturing in Rhino - only in Keyshot. The images I showed before are when I am using the UV editor and have a texture turned on.

Any update, @Jussi_Aaltonen ?

Is it KeyShot that asks you for texture size?

I meant the stock Rhino 7 UV coordinates, not Rhino 8. When I export the same model from Rhino 7 and Rhino 8 with the estFillInLegacyTextureCoordinates command, the scale is different. This may just be how the UV editor works in Rhino 8. I do not use a 1x1 square as Rhino 8 defaults to - I use a square that is true to size for the surface I am unwrapping. For example, If I had a 10x10x10 cube that I wanted to unwrap, the square for the UV editor would likely be 40x40 so that any textures I create in illustrator, for example, would be created in a 1:1 scale and exported. When mapped to the cube in keyshot, the stock 1:1 scale for UV mapping would show correctly. This behaves differently in Rhino 7 vs. Rhino 8 (with the estFillInLegacyTextureCoordinates command).

Regardless, this is not the real issue. The main issue is that Rhino 8 cannot export UV coordinates correctly without using the estFillInLegacyTextureCoordinates command.

To illustrate my 10x10x10 cube example:

Could you save a sample 3dm file with Rhino 7 that I can open and render in KeyShot and see the issue?

We decided to make a change in Rhino 8.9 that tries to duplicate the Rhino 7 behavior. Using the TestFillInLegacyTextureCoordinates should not be necessary anymore.

Hi @esmith1
Have you tested Rhino 8.9 or 8.10? KeyShot should show the correct mapping.