[Radiance-general] multiple processors

[Gregory J. Ward]

Hi Brett,
> Two questions:
>
> 1.
> If I do this:
>> rad -v single_view -N 5 myscene.rif
> Rad will *not* split up my scene for me (using rpiece).  However, if I
> specify multiple views, rad *will* run rpict multiple times
> simultaneously (ie. as forked/backgrounded processes).
> Is this expected behaviour? I was hoping it would split my scene!

This is the current behavior of rad.  I did not implement calls to  
rpiece with the -N option, only parallel rendering of multiple  
views.  Running rpiece properly and handling all the border cases,  
recovery, etc., is a bit complicated.  It would be nice to do in rad,  
but I haven't put it in there, yet.  Maybe when I have a 4-processor  
machine, it will seem worth my while.

> 2.
> Usually I use RIF files to store my "scene=", "illum=", "zone="
> variables, and to let rad handle calling oconv/rpict/pfilt/etc  
> correctly
> with appropriate settings.
>
> To divide up a scene, it seems I must use rpiece which calls rpict.
> (Let's *assume* my NFS lockd is working okay).  Therefore I cannot use
> rad and my rif files?  So I have to do what rad does *manually* and
> incorporate rpiece into this process?

If you run "rad -v 0 input.rif", it will call oconv and mkillum to  
generate the octree, without doing any renderings.  You can then pick  
up the job with rpiece at that point.

-Greg