[Radiance-general] Instances

[Lucio Boscolo]

Sorry Greg,

I feel a bit dumb, but still I'd like to understand this. 

If -PP is not sharing RAM, what memory is it sharing?

Thanks for your help again.


Lucio Boscolo Mezzopan
Assistant Designer  |  Lighting
       
Arup
13 Fitzroy Street  London W1T 4BQ  United Kingdom
t +44 20 7636 1531  d +44 20 7755 6311
f +44 20 7755 9012 
www.arup.com

-----Original Message-----
From: Greg Ward [mailto:gregoryjward at gmail.com] 
Sent: 07 January 2011 23:22
To: Radiance general discussion
Subject: Re: [Radiance-general] Instances

Hi Lucio,

> Thank you so much for your detailed answer (and sorry for being late again exploring it). 
> 
> -aa method is a good one, but I am a little concerned this will impact a lot on rendering time in a scene like mine in which many ab are required and a very high number of rays (it is a comparison between shading systems to work out transmittances).

It doesn't necessarily take as long as you might expect, because the ray tree is very sparse after the first bounce (depending on the -lw and -ld settings).

> The -PP option seems to be what I need, but I am not sure I understand it. Please tell me if the following is correct.
> 
> I start an rpict (or rtrace) with a -PP namefile option.
> 
> I start other rpict or rtrace wit -PP namefile (the same) and they will share memory (ram?)

Correct, although new ambient values will not share RAM.

> Ambient file instead will be shared by using -af and the same ambient file for all the processes.

This will share the values themselves, which is critical for speed if -aa is not 0, but they will take additional memory in each process.

> I believe -S is not needed with the -PP option, am I right?

With rpict, you need to couple -PP with -S.  The rpiece program takes care of dividing a single image into pieces if that is your desire.

> Can I share with -PP between rpict and rtrace processes?

Regrettably no, you need a separate syncfile for rpict and rtrace, as they are different executables.

Cheers,
-Greg
_______________________________________________
Radiance-general mailing list
Radiance-general at radiance-online.org
http://www.radiance-online.org/mailman/listinfo/radiance-general
____________________________________________________________
Electronic mail messages entering and leaving Arup  business
systems are scanned for acceptability of content and viruses