Secondary Ray Bias dilemma

[Reaversword]

Well, I'm trying to resolve all issues of my scene, but I fear I've founded a no-good-choose in my way.

I've a modern kitchen table, with a plastic plane under a crystal, and for other side, a crystal bowl containing some eggs.

I need establish the Vray "Secondary Ray Bias" parameter at 2 for get ride of this noisy bad illumination in the crystal table and down the render times at half. But then, eggs appears uncorrectly, with a uncorrect shadow and appearing that eggs are squashed against the crystal bowl.
Of course, if I leave the "Secondary Ray Bias" parameter at 0, render times gone duplicated, and noisy illumination appears, but egg bowl is correctly illuminated.

Nevermind if I separate a little bit more the table crystal from the plastic plane. This noisy illumination happens even in a shower where between the crystal door and ceramic background are about 80 cms and continues happening.

So, what's the move now?. Alternatives?. Which settings can fix both issues?

[vlado]

It looks like the noise is refractive GI caustics; does it go away if you turn on the "Affect shadows" option in the refraction section of the VRayMtl material?

Best regards,
Vlado

[Reaversword]

It is activated, in both, table and Bowl, but after trying activate/deactivate "Affect Shadows", I've launched a render of eggs & bowl separated.

Problem is in the eggs, nevermind kind of brdf, or completely lambert or reflective, incorrect shadows remains there. Except it I give to the eggs refractive, take a look at the render of crystal appearance, only then error doesn't reproduces again.

[vlado]

Can you get me that part of the scene to vlado@chaosgroup.com so that I can take a look?

Best regards,
Vlado

[Reaversword]

Done!, you have it in the mail.

[vlado]

Thanks, but I don't seem to be able to find that email?

Best regards,
Vlado

[Reaversword]

EggsBowl Secondary Ray Bias dilemma was subject.

Nevermind, here you have it

EggsBowl.zip

[vlado]

This is what I get with the latest nightly build. It might help to add a portal light at the window to reduce the splotchiness on the walls and turn off reflective GI caustics, but other than that it looks ok to me?

Best regards,
Vlado

[Reaversword]

No, Vlado, eggs appears uncorrectly.

Do next: A render, such you've done yet. Leave it in VFB history and change in Vray Settings, in the global options, change "Secondary Ray Bias" parameter from 2 to 0, and render again.

In first, you'll get, as you got yet, perfect table, wrong eggs. In second, you'll get correct eggs, wrong table, and double render time.

Yes, I need make some portals into the room, just for the cube of the test room I sended to you I didn't put it. Reflective caustics was only a marked option from the testing, trying to find a solution.

So basically, right now, we should choose or good table, or good eggs. We need a configurations for take both things working at the same time. But how?

[vlado]

Ah, ok, let me do some tests then.

Best regards,
Vlado

[vlado]

It looks like the "Detail enhancement" option for the irradiance map is to blame for this; turning it off makes things nice and fast again even when the secondary rays bias is 0.0.

Best regards,
Vlado

[Reaversword]

Humm.. I need to be more careful when I active something. I never imagined this was for Enhancement Details option of the Irradiance Map.

Vlado, thank you one more time. I know this is part of your job, but seriously, I'd like to return the favour some day. The list of solved problems keeps growing!. Incredible support, really.

[vlado]

No worries; glad I was able to help

Since the plane below the glass is too close to it, the detail enhancement is always used for it, essentially switching to brute force GI, which is what makes is so slow.

Best regards,
Vlado