HDRI loader can't load exr channels with layer names?

[Ihno]

I wanted to use the new exr -IO plugin for Photoshop to create myself a mipmap debug map.
That has a different color for every mipmap, so I can use it to see which mipmap is rendered where and how they blend.
Unfortunately the current version of exr - IO needs a layer name to properly export custom mipmapped images.
And if I load those files in the hdri loader it renders plain black.
Is the need for a layer name the reason? Or is there something else wrong with the file?
They want to fix that restriction in the next release. But I want to make sure it's the actual problem.

While we an on it, do you guys have a working version of such texture floating around by any chance?

[hermit.crab]

It seems that the VRayHDRI has troubles loading layered .exr files. I've made a note about it for our developers to look into. As a workaround, use a Bitmap instead.

[Ihno]

Jea but that'll remove the purpose since it doesn't support mipmapping at all, when I remember correctly. But thanks for the answer!
Will wait for the fix, either from your or from the exr -IO devs side.

[^Lele^]

It does mipmap, but not as well as the vrayhdri.
You should be able to split the layer you need with most post tools, though, to read it in the VRayHDRI loader.

[radoslav.platikanov]

You can also use the maketx tool to create a debug exr from separate images for the mip levels. This works by specifying the largest level as the input file, and specifying the mip levels using the --mipimage parameter for each level.