Im my current project it seems that all textures which are not perfect squares (for example 128 x 32) are constantly indicated ‘(not compressed yet)’ in the inspector even if the project has been built multiple times. Square textures (for example 128 x 128) appear to be compressed properly.
All the textures are using PVRTC 4 bit compression and automatic scaling to nearest power of two dimensions.
Is square dimension requirement for succesful compression or is there something else to do for these not compressing textures?
I am using iPhone Advanced version of Unity.
Thanks for any help.
AFAIK square power of 2 textures are required for PVRTC compression in Unity 1.0.1. It is possible to compress non-square POT textures on the iPhone, but it requires version 2.2 so I think we decided to leave it out for version 1.0.1.
This doesn’t exactly answer your question, but as an aside, also keep in mind that allowing the app to scale those textures isn’t going to look as good as doing them correctly from scratch (although with the small size of the iPhone you might not notice a difference). Even images resized in Photoshop won’t look as good once they are stretched.
Since pretty much all game engines nowadays require POT textures, a good practice to get into is to create texture “sheets” rather than individual textures: create a blank image that is a POT, then put your individual texture pieces into it, fitting them into the empty spaces, and UV map accordingly for the various objects it’s applied to. This takes a little extra work and planning, but it avoids any of those pixels getting squashed and stretched. This may also save a bit of load time, since the engine is loading one texture rather than several, but I’m not versed enough in iPhone dev yet to know if this will help. And obviously this won’t work for tiled textures.