In my Reality Composer Pro workflow for Vision Pro development, I’m using xcrun realitytool image to pre-compress textures into .ktx format, typically using ASTC block compression. These textures are used for cubemaps and environment assets.
I’ve noticed that regardless of the image content—whether it’s a highly detailed photo or a completely black image—once compressed with the same ASTC block size (e.g., ASTC_8x8), the resulting .ktx file size is nearly identical. There appears to be no content-aware logic that adapts the compression ratio to the actual texture complexity.
In contrast, Unreal Engine behaves differently: even when all cubemap faces are imported at the same resolution as DDS textures, the engine performs content-aware compression during packaging:
Low-complexity images are compressed more aggressively
The final packaged file size varies based on content complexity
Since Reality Composer Pro requires textures to be pre-compressed as .ktx, there’s no opportunity for runtime optimization or per-image compression adjustment.
Just wondering: is there any recommended way to implement content-aware compression for .ktx textures in Reality Composer Pro? Or any best practices to optimize .ktx sizes based on image complexity?
Thanks!