hopefully, this is a simple noob issue. Yes I have seen that it's been asked again and again and again, and I have tried lots of the solutions but I'm still stuck.
I have a model that I have applied a texture to and it renders nicely in Blender.
Ideally I want to export this to Shapeways for printing in colour sandstone, or when I eventually get an Mcor Arke, print it on there. So, I have a few options, DAE and X3D for example, these require the texture to be alongside the file in a zip file, and when I upload them, Shapeways says there is a texture (probably because the zip file included a PNG file), but won't render it. When I look in the X3D or DAE file with a text editor, there is no reference I can find to the PNG texture file.
I also tried this post on using the blender render engine, but it still doesn't have a reference to the texture when I export the object.
From when I used to do scanning, PLY seems to have all the image data in the file, so I tried that. Interestingly, Paint 3D recognizes PLY files and renders my bust scan... but, still no model of mine. I thought it may be the mirror modifier, but checking the export attributes, it applies those and includes the UV data, and I applied it manually to test anyway, but no.
Stumped, I continued my search. There was this post about not using nodes, but as I walked through the screenshots, I didn't have the "Mapping" tab that was there, then I did something somewhere and it was there, but it didn't have a UV option for coordinates, when I did the original unwrap I did use the smart option... because I followed a youtube example, so I went back to the beginning of this article, and did the unwrap.... but now I cannot see the material rendered at all in any view. I can't seem to find a walkthrough example of a complex paint job without nodes.
Finally, I found this post. I didn't really understand the explanation, but it did mention baking, which I saw in an option somewhere. So I gave that a pop.
Still nothing. So now I'm out of ideas. Any other ideas much appreciated, but, please bear in mind I still don't know Blender all that well.
If you're interested, here is a zip file with my .blend file and texture.
Any help much appreciated before I lose my mind.