Illums Causing Shadows

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)

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

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

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From: "Marcus Jacobs" <[email protected]>
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