[Radiance-general] silly question.. may be

[Gregory J. Ward]

Hi Guilio,

The -i option to rpict/rtrace only affects opaque, reflective  
materials.  It does not change the results for light sources or glow  
surfaces, or glass for that matter.

-Greg

> From: "Giulio Antonutto" <Giulio.Antonutto at arup.com>
> Date: July 25, 2006 11:53:43 AM PDT
> To: <radiance-general at radiance-online.org>
> just to double check...
>
> what happens if I have a glow or light  material on a surface and I  
> switch between illuminance and luminance calculation (rvu or rpict),
>
> Are the numbers going to change (from cd/sqm to lx) or are still  
> the same on the surface?
>
> I would expect that if I have 100cd/sqm I would get 314lx and to  
> see the number change.
>
> BUT It doesn’t seem to work this way, in fact the number still is  
> 100...
>
> I tried with rvu and the -i option do not affect this...
>
> I am thinking of a typical application where to save time and  
> energy you just stick a glow to a surface that has a known average  
> illuminance and it is lambertian... not terribly accurate but FAST.
>
> The results would look odd to me: the illuminance map would have a  
> 1/3.14 reduction for the values on the glowing surface...
>
> Is this ok?
>
>
>
> Ciao
>
> G>
>