Hybrid MLT+Bidir glass material is darker than CPU MLT+Bidir

[B.Y.O.B.]

Hi, out of boredom I made a test today to compare the speed of Hybrid vs. CPU.
The scene has 1,007,905 tris and each image was rendered for 20 minutes.

Yes, Hybrid is slower (GPU was a GTX 460 1GB), but what I also observe is that the Hybrid Bidir glass2-material is darker than in the other two renders.
I know, Hybrid Bidir isn't finished yet, but I just wanted to ask if this is already a known issue.

I also attached the scene.

[rendermagic]

I noticed a similar thing also a couple of weeks ago. I'm at my other job right now, so I don't have blender on this machine to look at your attached *.blend file. I think I remember having a problem with the metal materials too and it wasn't just the Glass material. Are you using a hemi light in your scene or even an area light? For whatever it's worth, I noticed that when I changed the output render resolution, I had varying results both good and bad. I wasn't able to pin point exactly what was causing it other than one common denominator....hybrid bi-dir.

[paco]

Just out of curiosity I don't suppose you did a CPU MLT + path?

[B.Y.O.B.]

Are you using a hemi light in your scene or even an area light?

The only light in the scene is a meshlight on the right hand side of the camera, the background is completely black.

Just out of curiosity I don't suppose you did a CPU MLT + path?

No I didn't, but I can make one if you want.

[paco]

Just out of curiosity I don't suppose you did a CPU MLT + path?

No I didn't, but I can make one if you want.

Yes please! I'd be very interested to see the result.

[B.Y.O.B.]

There you are

20 minutes MLT + Path (32 bounces, like the others).

[paco]

Thanks BYOB!

Looks the same as bidir to me, so the CPU side seems to working fine. Interesting stuff

[rendermagic]

Thanks BYOB!

Looks the same as bidir to me, so the CPU side seems to working fine. Interesting stuff

Exactly what I noticed. The CPU side seems to work exactly as expected when compared between bi-dir and path. The bug is constrained to bi-dir, specifically between CPU and Hybrid.I expect, however, that bi-dir is probably going to be a little buggy since it's still really new.