First, some stuff to look at:
This is what it should look like:
I’m messing with a nice piano model I found online (it needs a lot of fixing, but easier than making one completely from scratch, I guess. I plan to re-release it with all my updates, including the armature). I was adding the wood texture to the piano keys (piano keys should be made of wood, not just plastic). It is a standard 88-key baby grand piano, but I adjusted the model to only instance most of the keys. That is, each octave is a set of keys reusing the same mesh data.
So in order to make each key have a distinct grain, as you see in the second image, I just added the object offset to the texture coordinates, exactly as you see in the Shading Editor in the first image.
A quick switch from ortho to projective and I got what you see. I did nothing else before taking the screenshots, in the same order as displayed in this post, and there is nothing else particularly weird about the model.
(Well, I am using the Skin Modifier to generate the piano strings too, which is weird, I suppose, but I have had that working for quite a few iterations of this model’s updates, and restarts of Blender between working on it, before seeing this, so I think the probability of that being related is very low…)
It is just the one 3D Viewport that seems bothered. I suppose a restart of Blender will fix it. (If it doesn’t, I will definitely update this posting!)
Hmm, I just realized this is Blender 3.0.1. I’ve already updated to 3.4… seems I need to update my shortcut to start it… In any case, neither the terminal nor the Info window tell me anything has gone wrong (except for the stupid compile bug about EOF and <string>, which is not related).
I don’t know how to get any other useful information. Just thought I’d post this here, for… IDK. OGL glitch, maybe?