Hi Krzysztof, I'm interested to learn if you are successful at using Radiance to model parabolic reflectors. I presume you are trying to get an accurate distribution of the light fixture. When I have used Radiance to model light tubes such as tubular skylights, the ray-tracing method of Radiance breaks down after about 20 reflections--with only 7 surfaces! This means that light will not emit from the tubular skylight at angles between 180 degrees from nadir (grazing the ceiling) to 160 degrees. If many of your mirror polygons can "see" each other, then you may have the same problem. If you limit the number of reflections, then there is a certain amount of error introduced into the calculation for those rays that get "trapped". What is really needed is a forward ray-tracer. Have you tried the product called "Raydirect" that Georg Mischler and friends is providing? Georg, would it work for this application? -Chas

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From: "Krzysztof Wandachowicz"

To:

Date: Fri, 18 Apr 2003 18:09:50 +0200

Subject: [Radiance-general] set overflow in addobject

Reply-To: [email protected]

Dear Radiance users,

I have made calculation of luminance and illuminance distribution of specular reflectors using Radiance. My parabolic reflector is made with 15750 very small polygons. All polygons are mirror material. The problem is that when I make oconv process I get the following error:

oconv: internal - set overflow in addobject

(parabola-0-004-R_63E0.6350.1)

6350 is the number of polygon.

The same error I have on different computers and no matter if it is Radiance 3.1 under LINUX or Desktop Radiance.

Regards,

Krzysztof Wandachowicz

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Krzysztof Wandachowicz

Politechnika Pozna=F1ska, Instytut Elektrotechniki Przemys=B3owej

Zak=B3ad Techniki =A6wietlnej

http://lumen.iee.put.poznan.pl/kw/

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