[Radiance-general] Apparent inconsistency in rad when using the -N option

[Greg Ward]

Hi Terrance,

The trouble is that you are using the -i rendering option as if it  
were part of a view.  Very clever, and it works if you don't use the - 
N option of rad, but the mechanism behind the -N option with multiple  
views is that the view= variable is written to the stdin of an rpict  
running with the -S and -PP options, which shares memory on a  
multiprocessing platform.  In this mode, rpict just ignores any non- 
view options on stdin, which is why it isn't working as expected.

The latest HEAD allows you to run rad with -N on a single view (i.e.,  
"-v Plan" or "-v Plan-i" in your case), and it runs rpiece to split  
the work.  With your rad input file, you could run two rad processes,  
each with -N 4, one for each type of image, and get your job done in  
parallel that way.

I usually have a separate rad input file if I'm using the -i option,  
which I attach to the render= variable.  I had never thought of doing  
it your way.  Reprogramming rad to properly handle non-view options in  
view= settings would be a bit of work....

-Greg

> From: Terrance Mc Minn <t.mcminn at curtin.edu.au>
> Date: June 1, 2010 7:46:09 PM PDT
>
> Typically when creating irradiance images for falsecolor plots I set  
> up two views in the rif file:
> view= Plan -vf views/Plan.vf
> view= Plan-i -vf views/Plan.vf -i
>
> When rendering in rad via rad -N 8 studio1.rif the two images render  
> as radiance. The output from the rad command:
> rad -N 8 studio1.rif
> ...

> When rendering without the -N option in rad or (TRAD default  
> behaviour - yet to figured out how to specify the -N option for  
> trad) the output is the expected radiance and irradiance images. The  
> output from the rad command:
> rad  studio1.rif
> ...
> Version Head 2010-05-24
> on Mac OSX 10.6.3
>
> Notes:
> 1) For the compile the head didn't include the tiff source yet the  
> makeall still required it (copied the src/px/tiff folder from an  
> earlier download and recompiled).
> 2) To make trad run under OSX:
> mv ray/bin/trad ray/bin/trad-original
> new file ray/bin/trad
> #!/bin/bash
> exec wish /path_to_ray_folder/bin/trad-original "$@"
>
> Any ideas or have I misunderstood the usage of the -N option in rad.
>
> -- 
> Terrance Mc Minn
> Lecturer
> School of Built Environment
> Curtin University of Technology