Re: Shadows with pfLightSource

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Bernard Leclerc (bleclerc++at++cae.ca)
Fri, 16 May 1997 19:39:26 -0400

> Working with Performer and VEGA, we tried to modify shadow intensity by
> setting the PFLS_INTENSITY token of a pfLightSource to a specified value.
> The idea was to get some "grey" shadow (instead of black) when the
> intensity is reduced.
> But the effect we get is not the expected one: shadows remain black and
> it is just the lighting of the scene that is modified.
> Did I understand it wrong, or is there any side effect ?

The effect you observed is perfectly normal. PFLS_INTENSITY is used to
normalize the intensity of multipole light sources. If you want to change
the color of the shadow casted by the light source, you must specify the
ambient alpha with pfEarthSky:setColor() as mentioned on page 5 of the
pfLightSource man page. Refer to example 3 to setup a light source casting
semi-transparent shadows.

Bernard Leclerc, Technical Leader, 3-D Graphics Applications
CAE Electronics Ltd. (http://www.cae.ca)
8585 Cote De Liesse, Saint-Laurent, Quebec, Canada, H4L-4X4
tel: +1 514 341 2000 extension 2275, fax: +1 514 340 5496
              
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