Wrong brightness when mixing glass with roughglass

[Theverat]

Reported by Fox: https://forums.luxcorerender.org/viewtopic.php?f=4&t=1049
Scenes and blend file: mix_brightness_issue.zip

Glass:

Rough Glass:

Mix between both:
(mix amount is 0, so the result should be identical to the glass result)
Mix amount is 0.001, with glass being first and roughglass being second material.

[Dade916]

If I edit mix_brightness_issue/mix/scene.scn and set:

scene.materials.Surface_Lens__Glass__1_2218819541336.amount = 0.0

I get:

The same result I get from rendering mix_brightness_issue/glass/render.cfg:

Are you doing something different ?

[Theverat]

Sorry, my mistake, the mix amount is not 0, but in fact 0.001 (Blender UI cut off the last decimal).
By the way, scn files would be more readable if FILESAVER would not create all those implicit constfloat(3) textures.

[Dade916]

I should have fixed the problem.

[Theverat]

Thanks!