I’ve been testing ways to compress my skybox cubemaps (ktx files) using PVRTexTool, as found here:
(first I create a cubemap in PVRTexTool out of 6 images and then compress the cubemap using one of the listed compression methods).
These are the results I got, compatibility-wise, for different platforms with different compression methods:
What strikes me as interesting is that, on my actual macbook pro (intel chip) as well as on Browserstack, ETC2 compression method did not work (the skybox was not rendered). However, it does work on iOS.
Doing a little digging, I’ve found discussions about ETC2 on iOS, such as this:
Do iOS Metal devices have hardware… | Apple Developer Forums, which links to a Metal feature set here:
https://developer.apple.com/metal/Metal-Feature-Set-Tables.pdf , which seems to indicate that ETC2 is not support on macs:
However, these seem to indicate otherwise:
Can anyone verify that ETC2 does/does not work on macOS? (intel chips).
I feel like it would make sense for Apple to support it on mac if they do on iOS.
For reference, this is the playground I am using to test the different compression methods on different devices:
(#15 at the end of the url is dxt, #16 is etc1, #17 is etc2, #19 is astc, and #20 is pvrtc)