I need to apply a rectangular label onto a tube of lotion. The label text and photos looks correct when I do a standard unwrap (mark seam, select label, unwrap), however the label itself is distorted and not the proper shape. Shown below:
On the other hand, when I straighten my UV out with UV alignment tools (w > align), the label size and everything is right, but my text is stretched and not accurate.
This is a problem that also occurs in the real world. Some times, the distortion is minimal and the product is sold just like that; and sometimes the texture is distorted to adapt to the surface (a very typical case is printing labels for conical surfaces).
In 3D, you have a bit more ways to workaround, such as using UVs. But there’s no perfect solution for every case.
In your case, we could assume the surface of the tube was originally a cylinder, and therefor the length of all edgeloops (the perimeter) should be identical, which doesn’t happen and your second setup fails.
So you can choose to correct your mesh (either even the lenght of the edgeloops, or making some changes in the uv projection), or adapt your texture (Gimp and Photoshop let you warp textures).
Yes. Aligning the points like that is great for using up the uv space efficiently. But it will introduce distortion in that kind of shape. You could help it along by splitting the tube into two separate sections. Front and back. That might give the unwrapping algorithm something easier to work with. Think of it like a paper model that’s already assembled. If you just use one seam down the side and fold it out on a table, it’s not going to make a perfectly flat rectangle. As it’s not actually a cyclinder. The top and bottom have different widths.
What ever way you slice it, you may need to do some edits to the image to accommodate the model.
