Rhino 3dm file created from obj contains embedded texture but won't render with vray

I have this 3dm file created from obj which has a complex mesh geometry with texture mapping. In the preview mode I see bitmap texture mapped onto the geometry and it renders fine by rhino default renderer, but when I try to render it with Vray (Next) it renders as default gray mesh missing all the materials. I’ve been looking for the embedded mapping source in the 3dm file but I just can’t locate the mapping source from anywhere. I tried to save with ‘save textures’ feature but it doesn’t create any subfolders. Also tried ‘vraymtlfromrhino’ command but to no avail. Material property tab also doesn’t show any bitmap file linked to the material. But I know for sure that the file contains the source somewhere because it does render fine with rhino default renderer. Would someone know how I can fix this issue or at least where I can locate the bitmap source?

Thank you.

Best,
James

Hi James,

usually Rhino extracts the embedded texture files into “embedded files” folder next to the .3dm file. Please check if the location is writable and there is enough space available.

If you see the textures in the Rhino’s texture panel - which is probably not the case - you can see where the image files are located

You can try exporting the Rhino materials to .rmtl files and it will suggest you to embed or not the textures. Choosing the first and then inspecting the .rmtl (xml text file in fact) may give you some clues. The embedded textures are usually base64 encoded binary stream, which is easily decodeable by various online tools.

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Nikolay,

Thank you very much for the reply. I followed your instructions but to no avail. Meanwhile I also noticed that this is not the typical texture mapping via a bitmap source but rather a colored pixelation on the mesh object if that makes any sense. I’ve googled about this and the closest concept I could find was vertex coloring in Blender. If the file has been created in blender via the abovementioned method, would there be a workaround to extract the material or at least let it render in Vray? Please see attached images. Thank you so much.

Best,
James

Hello, James,

Could you please provide us with the scene for investigation? Even a tiny part of it would be sufficient.
You can archive the file by using the Rhino menu V-Ray > Pack Project and then send it over via a file-sharing service of your choice. Feel free to send it as a private message to me in this forum or as an email addressed to support@chaosgroup.com (with link to this forum thread).

Furthermore, please state the version of V-Ray you currently use and which engine you use (CPU/CUDA/RTX).

Kind regards,
Peter Chaushev
V-Ray for Rhino QA
www.chaosgroup.com

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Vertex colors can be displayed with V-Ray by using a material with a UVW map in its diffuse slot. The map channel must be to 0 (unless the data has been manually set to another uv channel).

Example:

Regards,
Peter

Peter,

Thank you very much. This is a lifesaver tip… and it totally works.

Best,
James