Space filler for UV

Is this possible?

I want to add a space filler, without editing the texture. Sort of non-uniform clamped tiling.

i do believe its possible and i remember seeing a video on it in the past but i couldnt tell you name. in the video though they took the uv space and divided it into smaller squares then set parameters for each square. i want to say it was for a procedural material video possibly done by epic.

this isn’t exactly what you’re asking for but I think it may work for you.
basically the material i’m linking takes the normal texture and sticks it in the corners. it stretches the texture a bit so it will map to a rectangular shape if needed.

divided it into smaller squares
it’s a Fmod node with 0.5 mult., but how to set parameters for each square - this is the main question

thanks for advice, but I have 1500 bolts head, so…

You may need to rearrange the mask to suite your purpose and get the right spacing pattern, but the number of bolts shouldn’t be an issue. I may just not understand what you’re going for though.