Why does UE4 Not Understand a Standard .dds HDR?

I’ve scoured the web searching for commercial free 360 HDR images to use as cubemaps in my project. The images I’ve located are all .dds format, and from what I can tell, most of these photographers seem to be using a standard setup to capture the 360 HDR image.

My question: Why doesn’t UE4 use what seems to be the standard for 360 images? In other words, why do I have to open the .dds in photoshop to flip and move each axis? (NEG-Z, POS-Z etc.)

Below, is what the .dds looks like in Photoshop.

Next is what it looks like when importing into UE4.


The map seems to be aligned wrong when used with a standard cubemap implementation.


I know about the UE documentation explaining how to flip the axis of each side, but I’m just wondering why the extra work to change what seems to be a standard for capturing the 360 images.

Thanks for any technical clarification on this.