[Radiance-general] mkillum implementation for light modifier (l+ switch)

[Greg Ward]

Hi Lars,

The 'l+' option to mkillum (that's that's a lower-case 'L,' everyone)  
turns designated surfaces into light sources, which as you say must  
include all components for correctness.  This will NOT produce an  
appropriate model for blinds that admit direct sunlight, but will be  
fine if sunlight is excluded by the blind angle or for diffusing or  
other surfaces where the direct component is negligible.

It's not merely for debugging purposes -- using light sources rather  
than illum's is appropriate under some circumstances.

-Greg

> From: "Lars O. Grobe" <lars.grobe at nus.edu.sg>
> Date: March 2, 2009 3:22:06 AM PST
>
> Hi,
>
> I have a question regarding the l+ switch for mkillum. As the light  
> modified surfaces as generated by mkillum with l+ block direct  
> light sources, the direct components should be included into their  
> distribution. At least if this is what they are made for. So is  
> this switch only for debugging purposes and does not change the  
> actual calculation done by mkillum, or does it also generate a  
> valid representation of the environment?
>
> Thanks & CU, Lars.