How can I use "monte carlo"

[f]

What the diferences between the monte carlo and the sandpaper sorted in the Bumps ?

[Roy Hirshkowitz]

The noise created by Monte Carlo is temporary-- it should eventually converge to smooth lighting if you let it cook long enough (and the material is smooth).  The noise generated by the bump maps is permanent and will not resolve.

 

[f]

thanks.  How can I use  the two  maps  lonely ?

[Roy Hirshkowitz]

The sandpaper bump useful for modeling rough surfaces-- Monte Carlo is only useful in some very specific situations-- I would use the Path Tracer instead if you want a more precise calculation.

[Ros. Riha]

Roy, please, could you point me to the place where it is described when and why should I choose Monte Carlo?

[Scott Davidson]

If you go to the Render settings tab you can select the Default or Path Tracer.  Select the path tracer.

[Ros. Riha]

I know. But I thought Monte Carlo is not being used generally in pathtracer. I thought I have to choose Monte Carlo as a shader in the material definition - my question was rather: Under which circumstances should I do so?

[Scott Davidson]

Oh, yes under reflection type. Monte carlo is there.  I have used monte carlo for situations that the default tracer creates big hard reflective brightspots that take a long time to resolve. I have seen it on table tops with a reflective finish that is high intensity and low sharpness, in a scene that has many small light sources in it.

[Roy Hirshkowitz]

 Some info here.  Not applicable to the Path Tracer.  It does a nice job w/ blurry reflections of light sources but does slow stuff down a lot.  Really can take a long time to converge with glossy surfaces.

[Ros. Riha]

thank you. So, if I understand well, once I use pathtracer, I do not have to worry about MonteCarlo...

[Roy Hirshkowitz]

Correct.  None of the other reflection shaders will make a difference either.

[Ros. Riha]

OK, thanks. Only two choices for pathtracer are "Balanced" and "Glossy", then...

How about No. of bounces in advanced render settings - does it affect pathtracer? Should I increase it to at least 2?