Could stickers be mapped instead of formed?

[N. W. Perry]

I think this would involve a considerable amount of code within the viewers and editors. Like TEXMAP for LDraw code.

Exactly, that was the basic genesis of the idea:

I was wondering about the usefulness of using normal type 1..4 lines to describe the pattern which a renderer can use to generate a texture. 

This would work much like embeded textures but instead of !DATA it uses normal ldraw code which must be 2d and flat.

I had the thought over the cases where primitive substitution is carried out and after that the hi-res prim cuts into the sticker...

Good point, you'd have to account for primsub both in the sticker pattern and the target part. I think it would just be a matter of doing the substitution first, before calculating all vertices, but perhaps you'd also need some regulations as to the allowable geometry of sticker patterns.

The trickiest part seems to be getting the proper 0.25 LDU thickness. But I think you would just ignore the stickerback geometry altogether; you'd just project the flat pattern surface directly onto the target part, generate a perimeter from that, and then translate the pattern surface 0.25 ldu on its own relative y-axis normal.

In other words, it would be the same process of creating a (printed) pattern by projecting LDraw code onto other LDraw code, just with the added step of building up the sticker thickness.