Creating UV layout for a non-square texture sheet
Often in gaming, we need to make non-square textures for environmental props. This requirement occurs due to one of the following reasons:
- Scene importance
- Object size
- Saving texture memory (reduce fill rate)
Many a times, I have seen artist laying out UVs in such a way for such textures sheet requirement that, though the texture seems fine on a model, it’s actually a stretchy non-square checker layout.
In this tutorial, you will see how the UV needs to be laid out to get perfect non-stretchable layout Texel density on the model.AS a base point I have a model (Machet weapon)
Based on its proportions and importance, I need a 512(w) X 1024(h) texture sheet. I have laid out the UVs like a normal layout with perfect square checker size.
Keeping the UVs on one half of the layout will not solve our problem because this means we are just using half of the complete texture that will be applied to the model.
To better understand, make a dummy 512X1024 sample checker texture sheet and apply it to the model. It will look like this:
This is a stretchy uv layout and to make it proper we need to scale the UVs non-uniformly to +U direction (in this case).
(For 1024X512 texture sheet, the UVs need to be scaled in +/- V direction.)
Here is an another example where I need 256X1024 texture sheet for the model and the UV layout need to be something like this.