POV-Ray : Newsgroups : povray.general : How to make film projector cone/spotlight Server Time: 29 Sep 2020 23:01:29 GMT
  How to make film projector cone/spotlight (Message 1 to 10 of 10)  
From: tmelram
Subject: How to make film projector cone/spotlight
Date: 17 Dec 2019 23:55:01
Message: <web.5df969e39d72d04361174e600@news.povray.org>
Hi, I'm trying to create a movie projector and have it project an image onto
onto other surfaces. I'd also like to have a cone shape volumetric effect for
the dust in the air near the projector. How would I go about this in POV Ray?


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From: Thomas de Groot
Subject: Re: How to make film projector cone/spotlight
Date: 18 Dec 2019 07:35:58
Message: <5df9d6de$1@news.povray.org>
Op 18/12/2019 om 00:50 schreef tmelram:
> Hi, I'm trying to create a movie projector and have it project an image onto
> onto other surfaces. I'd also like to have a cone shape volumetric effect for
> the dust in the air near the projector. How would I go about this in POV Ray?
> 
> 

Just thinking aloud, I would suggest to try the following:

1) use a spot light
2) as an image, use a plane/box intersection with an appropriate 
image_map, using some transparency
3) test how this projects upon a white screen (thin box or equivalent); 
probably not good enough (see below)
4) for dust in the air, use an isotropic scattering media

I don't know how this would work out, especially the projection on the 
screen. You might probably need to add/construct a lens with an 
appropriate interior and especially ior.

-- 
Thomas


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From: Paolo Gibellini
Subject: Re: How to make film projector cone/spotlight
Date: 18 Dec 2019 11:20:23
Message: <5dfa0b77$1@news.povray.org>
tmelram wrote on 18/12/2019 00:50:
> Hi, I'm trying to create a movie projector and have it project an image onto
> onto other surfaces. I'd also like to have a cone shape volumetric effect for
> the dust in the air near the projector. How would I go about this in POV Ray?
> 
> 

Mmmm. Years ago I made a little test on this subject, you can find it on 
p.b.s and adjust it following the suggestions of Thomas.
Hope it helps,
    Paolo


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From: Thomas de Groot
Subject: Re: How to make film projector cone/spotlight
Date: 18 Dec 2019 11:54:32
Message: <5dfa1378$1@news.povray.org>
Op 18/12/2019 om 08:35 schreef Thomas de Groot:
> Op 18/12/2019 om 00:50 schreef tmelram:
>> Hi, I'm trying to create a movie projector and have it project an 
>> image onto
>> onto other surfaces. I'd also like to have a cone shape volumetric 
>> effect for
>> the dust in the air near the projector. How would I go about this in 
>> POV Ray?
>>
>>
> 
> Just thinking aloud, I would suggest to try the following:
> 
> 1) use a spot light
> 2) as an image, use a plane/box intersection with an appropriate 
> image_map, using some transparency
> 3) test how this projects upon a white screen (thin box or equivalent); 
> probably not good enough (see below)
> 4) for dust in the air, use an isotropic scattering media
> 
> I don't know how this would work out, especially the projection on the 
> screen. You might probably need to add/construct a lens with an 
> appropriate interior and especially ior.
> 

Something I forgot to mention: photons might be what you want to use too.

-- 
Thomas


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From: jr
Subject: Re: How to make film projector cone/spotlight
Date: 18 Dec 2019 18:40:01
Message: <web.5dfa715fe2b94cab8c662f470@news.povray.org>
hi,

Paolo Gibellini <p.g### [at] gmailcom> wrote:
> tmelram wrote on 18/12/2019 00:50:
> > Hi, I'm trying to create a movie projector and have it project an image onto
> > onto other surfaces. I'd also like to have a cone shape volumetric effect for
> > the dust in the air near the projector. How would I go about this in POV Ray?
> >
> Mmmm. Years ago I made a little test on this subject, you can find it on
> p.b.s and adjust it following the suggestions of Thomas.

found the changes in output when rendering the scene for different '#version's
very interesting, only '3.6' gives me the expected result.  (using
alpha.10064268)


regards, jr.


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From: kurtz le pirate
Subject: Re: How to make film projector cone/spotlight
Date: 19 Dec 2019 16:36:35
Message: <5dfba713$1@news.povray.org>
On 18/12/2019 00:50, tmelram wrote:
> Hi, I'm trying to create a movie projector and have it project an image onto
> onto other surfaces. I'd also like to have a cone shape volumetric effect for
> the dust in the air near the projector. How would I go about this in POV Ray?
> 
> 

Hi,

Take a look at 
<http://www.f-lohmueller.de/pov_tut/interior/interior_20e.htm>


-- 
Kurtz le pirate
Compagnie de la Banquise


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From: Stephen
Subject: Re: How to make film projector cone/spotlight
Date: 21 Dec 2019 09:45:00
Message: <web.5dfde84ae2b94cab54809c2a0@news.povray.org>
"tmelram" <taj### [at] yahoocom> wrote:
> Hi, I'm trying to create a movie projector and have it project an image onto
> onto other surfaces. I'd also like to have a cone shape volumetric effect for
> the dust in the air near the projector. How would I go about this in POV Ray?

Is this the sort of thing you want? If so I'll look out the code.
Incidentally the "photograph" is one of Thomas's entries to TC-RTC.

https://i.imgur.com/Oqmn1.jpg


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From: Thomas de Groot
Subject: Re: How to make film projector cone/spotlight
Date: 21 Dec 2019 11:37:36
Message: <5dfe0400$1@news.povray.org>
Op 21/12/2019 om 10:41 schreef Stephen:
> "tmelram" <taj### [at] yahoocom> wrote:
>> Hi, I'm trying to create a movie projector and have it project an image onto
>> onto other surfaces. I'd also like to have a cone shape volumetric effect for
>> the dust in the air near the projector. How would I go about this in POV Ray?
> 
> Is this the sort of thing you want? If so I'll look out the code.
> Incidentally the "photograph" is one of Thomas's entries to TC-RTC.
> 
> https://i.imgur.com/Oqmn1.jpg
> 
> 
> 

LOL!

[still one of my images I am most proud of]

-- 
Thomas


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From: Stephen
Subject: Re: How to make film projector cone/spotlight
Date: 21 Dec 2019 17:00:01
Message: <web.5dfe4f21e2b94cab54809c2a0@news.povray.org>
Thomas de Groot <tho### [at] degrootorg> wrote:
> Op 21/12/2019 om 10:41 schreef Stephen:
> > "tmelram" <taj### [at] yahoocom> wrote:
> >> Hi, I'm trying to create a movie projector and have it project an image onto
> >> onto other surfaces. I'd also like to have a cone shape volumetric effect for
> >> the dust in the air near the projector. How would I go about this in POV Ray?
> >
> > Is this the sort of thing you want? If so I'll look out the code.
> > Incidentally the "photograph" is one of Thomas's entries to TC-RTC.
> >
> > https://i.imgur.com/Oqmn1.jpg
> >
> >
> >
>
> LOL!
>
> [still one of my images I am most proud of]
>
>

As you should be. :-D


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From: Paolo Gibellini
Subject: Re: How to make film projector cone/spotlight
Date: 8 Jan 2020 08:49:24
Message: <5e159794$1@news.povray.org>
jr wrote on 18/12/2019 19:35:
> hi,
> 
> Paolo Gibellini <p.g### [at] gmailcom> wrote:
>> tmelram wrote on 18/12/2019 00:50:
>>> Hi, I'm trying to create a movie projector and have it project an image onto
>>> onto other surfaces. I'd also like to have a cone shape volumetric effect for
>>> the dust in the air near the projector. How would I go about this in POV Ray?
>>>
>> Mmmm. Years ago I made a little test on this subject, you can find it on
>> p.b.s and adjust it following the suggestions of Thomas.
> 
> found the changes in output when rendering the scene for different '#version's
> very interesting, only '3.6' gives me the expected result.  (using
> alpha.10064268)
> 
> 
> regards, jr.
> 
> 
Curious. It was an old scene, I will get a look.
Thank you,
    Paolo


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