[Radiance-general] Illums Causing Shadows

[Gregory J. Ward]

Hi Marcus,

I attempt to explain why illum's cast shadows on page 573 of  
"Rendering with Radiance" (Figure 13.5).  The best workaround in your  
case is to use a combination of direct subsampling (-ds) and direct  
jitter (-dj) to make the shadows less noticeable.  In fact, they  
should be there, but they shouldn't be so sharp.  Turning on  
PENUMBRAS in rad will accomplish the same thing.

-Greg

> From: "Marcus Jacobs" <marcdevon at hotmail.com>
> Date: July 30, 2006 11:28:25 AM EDT
>
> Dear Group
>
> I am attempting to use illums in conjunction with translucent light  
> fixtures in order to produce smoother renderings. One problem that  
> I am having is that the illums themselves are causing shadows (see  
> here)
>
> http://i35.photobucket.com/albums/d178/marcdevon/ 
> room7a_day_Camera07_day_pcyl_tr3.jpg
>
> For the wall fixture, you can see the shadow of the spherical  
> illum. I am using a void material for the illum so it's invisible  
> to the eye but obviously not invisible to shadow rays. Is there any  
> work around for this?
>
> Thanks
>
> Marcus