Thanks for testing, I was hoping that would be the solution. I always thought TexConv uses the CPU by default, but I was only partially correct. For most compression types it does, but for BC6H/BC7 it uses the GPU unless disabled. Realizing that BC7 was the only format being corrupted put me on the right path, so thank you for that. But still it makes me wonder why it is working for me. I wonder if it has anything to do with installing the VirtualBox Guest Additions. I have it installed and 3D Acceleration enabled, maybe this is why I'm not seeing corruption; Oracle just might have their shit together.
If you want to try to get hardware acceleration working correctly just for the sake of trying everything or out of curiosity, here is the steps.
I enabled both 2D and 3D acceleration here. Unfortunately this is not enough for it to just work.
Windows VM may need to be started in Safe Mode depending on the version. Once booted Guest Additions ISO can be attached.
After checking Direct3D Support a message will pop up asking to use basic D3D support. I always press NO because I like experimental features.
And that's it. Finish up installing the drivers and reboot the VM. I'm not sure if you installed or, or even doing so will fix corruption for you when using GPU. But I figure now that we know the issue it might be worth seeing if this also fixes it.
I've just about finished replacing DDS Utilities with Nvidia Texture Tools, but it is disappointingly slow when it comes to creating BC7. Like, really really really slow. Converting a 2048x2048 texture took over 3 minutes! Using Compressonator or TexConv it takes less than 20 seconds. So I really don't see it as being ideal for anything other than a backup path for BC7. It is very fast with DXT1/5 and ARGB32 and creates nice textures there, so I suppose it still holds the same purpose as DDS Utilities with the added bonus of being able to create BC7.
If you want to try to get hardware acceleration working correctly just for the sake of trying everything or out of curiosity, here is the steps.
I enabled both 2D and 3D acceleration here. Unfortunately this is not enough for it to just work.
Windows VM may need to be started in Safe Mode depending on the version. Once booted Guest Additions ISO can be attached.
After checking Direct3D Support a message will pop up asking to use basic D3D support. I always press NO because I like experimental features.
And that's it. Finish up installing the drivers and reboot the VM. I'm not sure if you installed or, or even doing so will fix corruption for you when using GPU. But I figure now that we know the issue it might be worth seeing if this also fixes it.
I've just about finished replacing DDS Utilities with Nvidia Texture Tools, but it is disappointingly slow when it comes to creating BC7. Like, really really really slow. Converting a 2048x2048 texture took over 3 minutes! Using Compressonator or TexConv it takes less than 20 seconds. So I really don't see it as being ideal for anything other than a backup path for BC7. It is very fast with DXT1/5 and ARGB32 and creates nice textures there, so I suppose it still holds the same purpose as DDS Utilities with the added bonus of being able to create BC7.