Substance Designer can't export textures without an alpha

[FL_Alex]

I feel like this may be a bug but it could be an overlooked feature or even me missing something.

When Subsatnce Designer exports textures using Export Outputs, the images output will always have an alpha channel no matter what is input to the output and no matter what settings are used.

I've tried setting User Data to alpha=none which does not work.

I've tried using an Alpha Split node before ouput, despite only pumping in RGB Designer will still ouput an RGBA image.

I've also tried setting the Components to RGB rather than RGBA, Desiger seems to completely ignore this entirely for output exports.

Anything else that I am missing or is this just missing funcitonality or a bug?

It's worth saying that Substance Painter can handle not exporting Alpha so it's weird that Designer can't.

This is important for game development because RGB and RGBA images have different compression and cause different memory sizes.

[FL_Alex]

Investigated this more, it seems like this is actually a Unity problem and Designer is working correctly. The Unity compression selected is overriding the texture and showing as having an alpha when it does not. Feel free to close this bug.

[FL_Alex]

Ok, further investigation reveleaed that it is indeed a Unity issue. When set to High compression, Unity uses BC7 compression, there is only an RGBA version of this compression so it acts like everything has an alpha even though it does not.

Designer can export textures without alpha, all is well! Hopefully this info helps someone in the future.