Noise in Mental Ray (Max 9)

[studio2s]

ow, i forgot to say... Maximum Depth of 20 is for the overall amount of bounces... The Refl/Refr values are only for transparant rays...

--> so it gives you more bounced light = a lighter/smoother scene

 

nisus

 

A little clarification...is this like a secondary bounce?

 

Perhaps a better question is this: A diffuse bounce is the light at 100% (or with decay) and the trace depth is the number of secondary bounces each diffuse bounce ricochets around the scene?

[Justin Hunt]

Sorry to put your back up, it was the quote "As far as your RTFM...GFY." comment that tiped the scale, no need or place for that on this or any forum.

 

Put aside and forgotten now

 

Your explination of diffuse depth is almost right, Think of it as how deep you want the samples to get into a scene.

 

The diffuse depth at 5 is dark and lacking detail, at 25 the shadows are brighter and more detailed and at 250 light is reaching right back into the recess and there is good detail, but the highlights are starting to blow out.

 

Its subtle so load all three images into photshop and look at them side by side for a better comparison

 

JHV

[studio2s]

Sorry about that.

 

 

Man, I have to tell you, I can't see a difference. Part of that my be that I am forced to use these awful flat screens. Even if I think I see a difference, it may be that I am THINKING I see a difference.

 

Is there any hit at all in the render time? Even if there is a difference, I'm not sure it is worth the effort. I don't think I would be able to tell if you aren't telling me it's different.

 

Are you trying to play a joke?

[Justin Hunt]

Its not the best example, just knocked it up quite qickley.

 

I did come across a tut the illistrates it better, but I'll have to fish it out.

 

It doesn't hit the render time at all, but the results are well worth the settings. 5 is too low as a default (remblance of days long past) as a rule I start at 20 and sometimes go up to 50, although I have never gone to 250 in production.

 

Try the test yourself to make it clearer than my sad attempt

 

JHV

[nisus]

Here is another example:

 

5 Bounces

 

10 Bounces

 

[Justin Hunt]

much better;)

 

JHV

[studio2s]

WOW...that is markedly better. How many diffuse bounce do you have in that nisus?

 

I just tested a scene at 20 and then at 1000, and could see no difference.

 

Perhaps it is also reliant on other factors in your scene?

[nisus]

the real difference is in the LOW amount of bounces...!

 

the more bounces, the less energy gets around...

the difference between NO or 1 bounce is large... When every bounce loses 20% of energy as an example... the first one will be able to add up to 80% of the energy, the second the second bounce only 64%, etc... every extra bounce will add less and less to the scene...

Also contrast-levels will disappear... everything will become more flat because there is ligth everywhere...

It's a but tricky, but stay low!

 

The tutorial states an average of 5 to be good, 10 for lighter rooms, 3 for darker rooms... I found this to be really true...

 

rgds,

 

nisus