Normal maps forced to be 4-channel (RGBA), even on mobile?

Unity Engine
1

Hi,

I’m experimenting with normal maps on mobile, and have noticed that Unity forces them to always be 4-channel (RGBA).

This means that on Android, I can only choose RGBA4444 or RGBA8888 - neither of which is ideal. I want to try RGB565 or ETC1. Is there any way to do this?

I understand why an alpha channel is needed on high-end platforms (as the normals are stored in the green and alpha channels, for optimal DXTC compression) - but on mobile, only the RGB channels are used, yet I can’t select an RGB-only format, even as an Android-only override?

Am I doing something wrong/is there a workaround for this?

2

this will be changed in 4.2

3

Thank you, that’s good news!