Max ray intensity > darker image

[chickensalad]

Hi!

I have been working on a interior - a hallway of a house, pretty small windows and overcast HDRI in a domelight as main lightsource. BF/LC. Vray version 3.20.03.
The scene has been to dark since I started working on it and I could not get why. I seemed like enough light wasn't getting in. But anyway, I unticked the Max ray intensity checkbox and the image is now alot brighter. I had a float value of 0.3 or something in the corner furthest away from the window with MRI on, set to 20. Now with it unticked its around 0.85.

Are there cases where you shouldnt use MRI? Or does sound like I screwed up somewhere along the way?

Cheers!

[vlado]

It is normal for MRI to produce a slightly darker image; in most cases this is barely noticeable, but there are some scenes where the effect may be bigger.

Are you using a dome light with the HDRI?

Best regards,
Vlado

[chickensalad]

Ok! Thanks for the quick reply.

Yes, a domelight is used with the HDRI

[vlado]

Ok, then it's a bit odd. You have glass at the windows I guess? Is there any difference if you remove it?

Best regards,
Vlado

[chickensalad]

Yes, glass in the windows! Dont know if there is a difference without them. I will look in to it tomorrow morning when Im back in the office!

[chickensalad]

Hi again!

I tried about everything to see If something in my scene casued it. Reset the Vraysettings, removed the window glass, override the material, merged only the walls and floor in a new scene and so on. Nothing.

I even reproduced it a new scene, just a box with 2 holes in it, shell modifier and a teapot inside. 10x10x2,5m in size. An HDRI in a dome light. One thing I eventually noticed was that the difference between MRI on an off increased along with the shutter speed.

I attatched a long image I hope explains it a bit.

Info:
The four first image is almost Vray default settings, only switched to adaptive and set the burn value to 0,05 (Tried with one and same result). This is part of the scene I first talked about, the hallway.

The two last images, a crop of a bathroom scene is somewhat universal settings. Burn value also 0,05. HDRI in a dome and some IES profiles.


I dont know that to do The difference in the bathroom scene is pretty huge!

Added:
Perhaps its the Burn value workflow that screws it up...?

[vlado]

It would be best if you can get us some example scene to support@chaosgroup.com so that we can check if there's anything wrong.

Best regards,
Vlado

[chickensalad]

Mail sent. Looking forward to see what you find. Thanks!

[Oleg_Budeanu]

having the same thing here - scenes are looking darker , but i thought that is like a usual max. ray intensity behavior ?

[svetlozar.draganov]

having the same thing here - scenes are looking darker , but i thought that is like a usual max. ray intensity behavior ?

Can you show us how much is the difference?
A small difference is a normal behavior but large one might be a bug.

[Micha]

Last I did a test with the ray max intensity feature at VfR3 and it cause a darkening too. My impression is that this feature cut's the lighting of emitter materials and HDRI environments. Is it so?

For example if I use emitters intensity 80 and set ray max intensity 20, than I get the same result like emitter intensity 20, right? If yes, than this feature could be good for cutting the sun intensity of HDRI only, right?