Hi

tried to generate a 'white laser beam' through a prism (black sourrounding,
windows xp) watching for the dispersion (Factor 1.5, samples 15). The laser
beam should be visible by scattering in a dusty air media. Unfortunately the
laser beam generated by a spot light is only visible before hitting the prism
surface but not visible after passing the prism. Any ideas why this happens? I
have only one air media specified with IOR=1, scattering on, mie hazy,
extinction 0.1, scattering color grey 0.86 lum.
The beam should be light enough to show at least some scattering. Any ideas what
to improve?

Thanks MRe

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MRe napsal(a):
> Hi
> 
> tried to generate a 'white laser beam' through a prism (black sourrounding,
> windows xp) watching for the dispersion (Factor 1.5, samples 15). The laser
> beam should be visible by scattering in a dusty air media. Unfortunately the
> laser beam generated by a spot light is only visible before hitting the prism
> surface but not visible after passing the prism. Any ideas why this happens? I
> have only one air media specified with IOR=1, scattering on, mie hazy,
> extinction 0.1, scattering color grey 0.86 lum.
> The beam should be light enough to show at least some scattering. Any ideas what
> to improve?
> 
> Thanks MRe
> 
> 
see photons in the documentation.

Post a reply to this message

MRe napsal(a):
> Hi
> 
> tried to generate a 'white laser beam' through a prism (black sourrounding,
> windows xp) watching for the dispersion (Factor 1.5, samples 15). The laser
> beam should be visible by scattering in a dusty air media. Unfortunately the
> laser beam generated by a spot light is only visible before hitting the prism
> surface but not visible after passing the prism. Any ideas why this happens? I
> have only one air media specified with IOR=1, scattering on, mie hazy,
> extinction 0.1, scattering color grey 0.86 lum.
> The beam should be light enough to show at least some scattering. Any ideas what
> to improve?
> 
> Thanks MRe
> 
> 
Another thing to tryb is to use object media (as tight as possible) 
instead of global media whenever possible. This improves the quality a 
lot. But that's not necessary in your case

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MRe nous apporta ses lumieres en ce 2007/11/04 15:24:
> Hi
> 
> tried to generate a 'white laser beam' through a prism (black sourrounding,
> windows xp) watching for the dispersion (Factor 1.5, samples 15). The laser
> beam should be visible by scattering in a dusty air media. Unfortunately the
> laser beam generated by a spot light is only visible before hitting the prism
> surface but not visible after passing the prism. Any ideas why this happens? I
> have only one air media specified with IOR=1, scattering on, mie hazy,
> extinction 0.1, scattering color grey 0.86 lum.
> The beam should be light enough to show at least some scattering. Any ideas what
> to improve?
> 
> Thanks MRe
> 
> 
You need to enable photons. Search for photons in the documentation.
You need to set the prism as target and turn on refraction.
You don't need to add anything to your light.

A dispersion of 1.5 is prety strong, a realistic value should be more in the 
1.01 to 1.1 range. You don't need to set the ior for the "air".

-- 
Alain
-------------------------------------------------
I believe that banking institutions are more dangerous to our liberties than
standing armies. Already they have raised up a monied aristocracy that has
set the government at defiance. The issuing power should be taken from the
banks and restored to the people to whom it properly belongs.
Thomas Jefferson

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