Vray 3.6 Rhino - DOME LIGHT + HDRI - noise and sharpness problem

[tsponti]

Hi,

I just installed the Vray 3.6 for Rhino Trial and I have some problem because I don't find all the settings I used on Vray 2 (see attached please)

1- I am used to Irradiance Map in first bounce with 3 prepass (see attached please) and now I don't find how to have more than just one prepass.
I have a lot of noise in a simple image (see attached the "Vray3.6" test vs the "Vray 2 test") and not a lot of sharpness.

maybe the problem is coming from the subdivision of the dome light - in Vray 2 there was a setting and I used a subdivision of 22.

2 - One other thing, I was used to have a GI postprocessing saturation of 0.3 and a contrast base of 0.5, and I don't find anymore this option.

3 - for the dome light, is there a difference between "dome light at ppoint tool" and "dome light as sphere tool" ?

Can you help me for those problem?

thanks a lot for your help.
kind regards,

thomas

[mgibeault]

Hi Thomas,
The best would be to not try to replicate V2 settings. 3.6 is different enough and a lot of optimization has been made and you should use them to get better renders and faster times.
Start by using the defaults; use the "Revert to default render settings" button and use the Quality slider to select the level you need.
Leave some noise in the image, often time Medium quality is enough, and switch on the denoiser.

[Micha]

I would be careful with the quality slider. It's a pitfall, since it control a mix of options.

For example you have GI splotches, so you would need to use some more IM subdivs, but per slider you get a stronger noise limit and much to long render times. Same problem if you want to avoid some noise and the slider grow up the GI samples. Better, the user learn to avoid noise and splotches by the right options.

[mgibeault]

You're right Micha, it's best to know all the options!
But it's better to start with a clean slate, that's the reason I recommend resetting to defaults first. For example, in 3.X, I don't use IM anymore. LC/BF has been faster, with better result and less options to worry about, for both interior and exterior renders.

[Micha]

You're right Micha, it's best to know all the options!
But it's better to start with a clean slate, that's the reason I recommend resetting to defaults first. For example, in 3.X, I don't use IM anymore. LC/BF has been faster, with better result and less options to worry about, for both interior and exterior renders.

Sounds very promising. I must test it at my my next test round.

[tsponti]

Hi,
thank you guys.
I started a new file with no settings, and did my own settings directly customing the presets.
now It seems to work good and the denoiser is great.

one question for you about the Dome Light HDR rotation : is it right that in Vray 3.6 the Rotate H works in reverse from the previous version? (to have 30 degrees, you must now type -30 degrees)

thanks for your answer.