Potential IBL regression

[ApoorvaJ]

The behavior of --envRad has significantly changed between the last two versions. I'm not sure if this is a regression.

This only happens when an irradiance image file is not found. In both versions, I get the warning: Image file not found: /path/to/MaterialX/irradiance/foo.hdr. But in the newer version, the result is much darker.

Is this a bug or is it on purpose?

Command: bin/Debug/MaterialXView --material "Emerald_Peaks_Wallpaper.mtlx" --envRad "foo.hdr"

On v1.38.7:

On v1.38.8:

The material can be found here.

[jstone-lucasfilm]

Good catch, @ApoorvaJ, and I'm testing a proposed fix for this issue, which we can integrate into MaterialX 1.38.9.

[jstone-lucasfilm]

Fixed in #1647.