POV-Ray: Newsgroups: povray.general: Spotlights render faster than point lights?

POV-Ray : Newsgroups : povray.general : Spotlights render faster than point lights?		Server Time 4 Nov 2024 12:58:50 EST (-0500)

From: Greg M Johnson
Subject: Spotlights render faster than point lights?
Date: 18 Nov 2003 23:14:27
Message: <3fbaee23$1@news.povray.org>

I had a complex scene, with three spotlights pointed at the center: it took
122 secs to render.
But with three point lights, it took 133 secs.

Soooo,  is it true that if one wants spotlights for dramatic effect, it can
only be a render time-helper?

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From: Christopher James Huff
Subject: Re: Spotlights render faster than point lights?
Date: 18 Nov 2003 23:32:00
Message: <cjameshuff-E7BA9D.23284818112003@netplex.aussie.org>

In article <3fbaee23$1@news.povray.org>,
 "Greg M. Johnson" <gregj;-)565### [at] aolcom> wrote:

> I had a complex scene, with three spotlights pointed at the center: it took
> 122 secs to render.
> But with three point lights, it took 133 secs.

For all the areas outside the cone of light, no shadow testing needs to 
be done. And it's computationally cheap to figure out that a point is 
outside the cone of light. 

> Soooo,  is it true that if one wants spotlights for dramatic effect, it can
> only be a render time-helper?

If a spotlight illuminates practically the entire visible scene, it will 
be slightly slower. (Extra calculations for spotlight angle falloff, no 
benefit from skipping shadow calculations.)

Otherwise, render time will be slightly faster.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/

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