I have tested the new basis compression and I can’t get a decent result, no matter what settings I use (including the quality setting). Are there any tricks I don’t know to get better output quality? Or is it a bug?
Here is the screens :
Thanks
I am really using the KTX2 Binaries running toktx
The latest packaged version was Beta 5. Maybe it has issues.
There is a 4.0.0 Release build… I will update the KTX2 command lines tools
in the next Babylon Toolkit. See that that helps
Also… These are the command line args i am passing to toktx.exe command line tool.
If you know of any changes or other commands… let me know
commandLines = new string[] {
" --t2",
" --bcmp",
" --clevel " + compression.ToString(),
" --qlevel " + quality.ToString(),
" \"" + outputPath + "\"",
" \"" + inputPath + "\""
};
You should use the uastc flag instead of bcmp for non color textures like normal map or metallic/roughness texture (see slide 6 here) or maybe provide an option to use uastc for such textures (a user may still want to use etc1s for all types of textures if the file sizes are more important than the rendering visual quality).
Ca you give example of command line(s) for these types for the toktx.exe ?
Two command lines I have used:
toktx.exe --t2 --genmipmap --uastc 2 testalpha_uastc detailmap.png
toktx.exe --t2 --genmipmap --bcmp testalpha_etc1s detailmap.png
That is much better… still a little artifacts, but much better
I will make two command lines… One for default images and one for normal map and metallic roughness textures
Thanks @Evgeni_Popov for all the great info 
New KTX2 Export options (Will be in next toolkit update):
Now you have whatever formatting you want for both default images and non color images
Seems awesome, thanks !