[Radiance-general] instance primitive & xform

[Gregory J. Ward]

Hi Jelle,

The -a option is supported by xform, only.  When it is applied, xform  
replaces a single file with many copies, each using the -i option to  
indicate how many times to apply each transform.  In short, you need  
to create a file with a single instance in it and call it using ! 
xform with the -a option to get multiple copies.

Be sure to pay attention to the tips in the reference manual <http:// 
radsite.lbl.gov/radiance/refer/ray.html#Surfaces> about when and how  
to use instances.  In particular, instances work best with cubicle  
volumes (ideal) or at least square-ish pieces to avoid too many  
overlapping instance boundaries, which are always cubes.

-Greg

> From: "Jelle Feringa / EZCT Architecture & Design Research"  
> <jelle.feringa at ezct.net>
> Date: September 25, 2006 8:48:49 PM BDT
> Hi!
>
> I just tried to use the powerful ‘instance’ primitive, which is  
> working fine unless I try to use a repeated (array) transform:
>
> void instance 001
>
> 8 ./Oct/s_enn.oct  -a -t 0 0 0.0064 -i 200
>
> 0
>
> 0
>
> Results in:
>
>
>
> oconv: fatal - bad transform for instance "001"
>
>
>
> So clearly I’m doing something wrong here…
>
> As far as I understand I do need the –a flag to repeat transform,  
> right?
>
>
>
> I’m testing a scene with very, very dense louvers, which is a  
> perfectly suitable case for instances I reckon.
>
> For this scene I’m required to use the pmap/radzilla fork of Radiance.
>
> Am I assuming correctly that the ‘instance’ primitive is supported  
> in (either?) of these versions?
>
>
>
> Cheers,
>
>
>
> -jelle
>