We're trying to reduce the size of our app on all platforms, but especially on Android, so I made a tool that iterates through all of the texture importers, sets them to override with an appropriate crunch compression algorithm for the given platform, and re-imports the asset. On Windows Standalone builds this has had a dramatic impact but on Android it seems barely worth it.
I am trying to figure out if I'm doing something wrong or if there is a significant difference in how much crunch compression impacts build size between Standalone Windows and Android.
Here are my results:
Standalone Windows Before Crunch Build Size: 1.34 GB After DXT5 Crunch Quality 75 Build Size: 647 MB
~48% of the pre-crunched size
Android Before Crunch OBB size: 574 MB After ETC2 Crunch Quality 75 OBB size: 517MB
~90% of the pre-crunched
We're using Unity 2019.2.21f1 and on both platforms we're using Asset Bundles on the same set of assets. The only thing I can think of is there is something specific about Android or the ETC2 algorithm or my configuration that's causing such a vast difference in how effective crunch compression is.
Does anyone have any thoughts about where I might be going wrong?
I've looked around quite a bit but only really seeing people posting that crunch compression should have a dramatic effect even on Android.