Can anybody help?

want to create a scene with a lens that is focusing the light.

The scene could look something like this:
 A cylindrical light source
 A aspherical lens between the source and a plane or a box (just so I can
simulate the interaction between light and the lens) .

How can I align the properties of a lens/to the lens?

I ain't got much time in experimenting, so I would be rather thankful for
any assistance

Marvin

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You will want something like that:

#version unofficial megapov 0.7

#include "colors.inc"
#include "glass.inc"

global_settings{ 
        max_trace_level 100
        adc_bailout 1/32
        photons{
                count 20000
                autostop 0
                jitter .4
        }
}

camera{
        location <0,10,-10>
        look_at <0,2,0>
        angle 30
}

light_source{<10,100,0>
        color White
        spotlight
        radius 2
        falloff 2.1
        point_at <0,2,0>

        // or use the following for a cylindrical light, but gets somehow too 
bright
        /*cylinder
        radius 10
        falloff 15
        point_at <0,2,0>*/
}

plane{y,0
        pigment{Red}}

// this is acutally not a realistical lens but just a scaled sphere
// - you will probably want to use an intersection between two spheres

sphere{<0,0,0>,1
        scale <1,0.05,1>
        rotate z*-40
        translate <0,2,0>
        texture{T_Glass3}
        interior{I_Glass}
        photons{
                          target                                
                          reflection off
                                refraction on
                          ignore_photons
                          }   

}

// EOF

Note that it *requires* the unofficial version 'MegaPOV'. I guess you 
already got it but in case you do not go to 
http://nathan.kopp.com/patched.htm

- Micha

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"Micha Riser" <mri### [at] gmxnet> wrote in message
news:3b65cd4f@news.povray.org...
>
>         photons{
>                           target
>                           reflection off
>                                 refraction on
>                           ignore_photons
>                           }

    Seeing this has reminded of something I didn't understand when I looked
at photons - What does ignore_photons do ? From the docs, it seemed to me
that it instructed MegaPOV to completely ignore photon interactions with the
object it's declared in, but then it recommended using it in glass or other
transparent objects - surely transparent objects are exactly those that you
want the photons to interact with, no ?

--
Scott Hill.
Software Engineer.
E-Mail        : sco### [at] innocentcom
Pandora's Box : http://www.pandora-software.com

*Everything in this message/post is purely IMHO and no-one-else's*

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D'Oh, forgot to set follow-ups to p.u.p...

--
Scott Hill.
Software Engineer.
E-Mail        : sco### [at] innocentcom
Pandora's Box : http://www.pandora-software.com

*Everything in this message/post is purely IMHO and no-one-else's*

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I think that ignore_photons means that no photons are _stored_ in the
surface of the object in question. The object still affects the direction
of the photons.

-- 
#macro N(D,I)#if(I<6)cylinder{M()#local D[I]=div(D[I],104);M().5,2pigment{
rgb M()}}N(D,(D[I]>99?I:I+1))#end#end#macro M()<mod(D[I],13)-6,mod(div(D[I
],13),8)-3,10>#end blob{N(array[6]{11117333955,
7382340,3358,3900569407,970,4254934330},0)}//                     - Warp -

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thank you very much!

You seem to have the knowledge about the program.
Perhaps you could you help me with the intersection problem on the sphere
aswell?

The sphere should have a radius on 206 mm, making a lens with 90mm in
diameter, when you intersect it. (this leaves a lens thicknesson approx.
7mm)

Thank you for your help, I really appreciate it.

Marius


Micha Riser <mri### [at] gmxnet> skrev i
meldingsnyheter:3b65cd4f@news.povray.org...
> You will want something like that:
>
> #version unofficial megapov 0.7
>
> #include "colors.inc"
> #include "glass.inc"
>
>
bal_settings{ 
>         max_trace_level 100
>         adc_bailout 1/32
>         photons{
>                 count 20000
>                 autostop 0
>                 jitter .4
>         }
> }
> 
> camera{
>         location <0,10,-10>
>         look_at <0,2,0>
>         angle 30
> }
> 
> light_source{<10,100,0>
>         color White
>         spotlight
>         radius 2
>         falloff 2.1
>         point_at <0,2,0>
> 
>         // or use the following for a cylindrical light, but gets somehow too 
> bright
>         /*cylinder
>         radius 10
>         falloff 15
>         point_at <0,2,0>*/
> }
> 
> plane{y,0
>         pigment{Red}}
> 
> // this is acutally not a realistical lens but just a scaled sphere
> // - you will probably want to use an intersection between two spheres
> 
> sphere{<0,0,0>,1
>         scale <1,0.05,1>
>         rotate z*-40
>         translate <0,2,0>
>         texture{T_Glass3}
>         interior{I_Glass}
>         photons{
>                           target                                
>                           reflection off
>                                 refraction on
>                           ignore_photons
>                           }   
> 
> }
> 
> // EOF
> 
> Note that it *requires* the unofficial version 'MegaPOV'. I guess you 
> already got it but in case you do not go to 
> http://nathan.kopp.com/patched.htm
> 
> 
- Micha

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