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29 Mar 2024 01:58:04 EDT (-0400)
  A Dahlgren Projector. (Message 1 to 10 of 10)  
From: Stephen
Subject: A Dahlgren Projector.
Date: 29 Jul 2016 18:40:01
Message: <579bdb41@news.povray.org>
On another thread I was discussing the book Dahlgren with Thomas.

This is my first attempt at making a light projector. It projects a 3D 
image of a large insect around who is wearing it.
I used a df3 density file that I made from a Poser model of a scarab. 
Then put it in a emitting media container.

Comments welcome.

-- 

Regards
     Stephen


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From: Thomas de Groot
Subject: Re: A Dahlgren Projector.
Date: 30 Jul 2016 02:46:57
Message: <579c4d61$1@news.povray.org>
On 30-7-2016 0:39, Stephen wrote:
> On another thread I was discussing the book Dahlgren with Thomas.
>
> This is my first attempt at making a light projector. It projects a 3D
> image of a large insect around who is wearing it.
> I used a df3 density file that I made from a Poser model of a scarab.
> Then put it in a emitting media container.
>
> Comments welcome.
>

That is how I imagined it to be. Well done indeed.

-- 
Thomas


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From: architype
Subject: Re: A Dahlgren Projector.
Date: 30 Jul 2016 03:05:01
Message: <web.579c50f03dc632c9d6e6ad910@news.povray.org>
Thomas de Groot <tho### [at] degrootorg> wrote:
> On 30-7-2016 0:39, Stephen wrote:
> > On another thread I was discussing the book Dahlgren with Thomas.
> >
> > This is my first attempt at making a light projector. It projects a 3D
> > image of a large insect around who is wearing it.
> > I used a df3 density file that I made from a Poser model of a scarab.
> > Then put it in a emitting media container.
> >
> > Comments welcome.
> >
>
> That is how I imagined it to be. Well done indeed.
>
> --
> Thomas

Yup, very good work.
I cant comment much though, because I rarely mess with the tricky lights and
material stuff. /A


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From: Thomas de Groot
Subject: Re: A Dahlgren Projector.
Date: 30 Jul 2016 03:08:45
Message: <579c527d$1@news.povray.org>
I have dusted off my Dhalgren. Time to get seriously to work...

-- 
Thomas


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From: Stephen
Subject: Re: A Dahlgren Projector.
Date: 30 Jul 2016 05:57:57
Message: <579c7a25$1@news.povray.org>
On 7/30/2016 7:46 AM, Thomas de Groot wrote:
> On 30-7-2016 0:39, Stephen wrote:
>> On another thread I was discussing the book Dahlgren with Thomas.
>>
>> This is my first attempt at making a light projector. It projects a 3D
>> image of a large insect around who is wearing it.
>> I used a df3 density file that I made from a Poser model of a scarab.
>> Then put it in a emitting media container.
>>
>> Comments welcome.
>>
>
> That is how I imagined it to be. Well done indeed.
>


Thanks, I am quite pleased how it turned out.

I refined how I make df3's as well. I use the slice method taking three 
passes. One for each colour channel. But there has always been a colour 
imbalance with the red channel being the weakest.
After the discussion last week and understanding it a bit better. I 
found a way around.
My photo editor (PSP 9) has an adjustment called "Channel Mixer". There 
you can take one colour channel from the image and mix it across all of 
the channels*. Mitigating PovRay's method of turning a vector into a 
scalar value. I think I might be able to cut out two of the three 
initial passes using that adjustment in batch mode. :)

I thought I would share before I forget.


* This method can also be yours. Send only one dollar and a S.A.E. to 
the following address... ;)


-- 

Regards
     Stephen


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From: Stephen
Subject: Re: A Dahlgren Projector.
Date: 2 Aug 2016 15:34:24
Message: <57a0f5c0@news.povray.org>
On 7/30/2016 10:57 AM, Stephen wrote:
> Thanks, I am quite pleased how it turned out.


I'm not so pleased with the Dragon Lady.

This is the best I could do with this model. I can't get rid of the 
stripes. :(

Two days, 19 df3s and umpteen gigabytes later.

But then the books said.
"They were, he realized, as eye-unsettling as pictures on a 
three-dimensional postcard—with the same striatums hanging, like a 
screen, just before, or was it just behind them."



-- 

Regards
     Stephen


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From: Thomas de Groot
Subject: Re: A Dahlgren Projector.
Date: 3 Aug 2016 02:51:53
Message: <57a19489$1@news.povray.org>
On 2-8-2016 21:34, Stephen wrote:
> On 7/30/2016 10:57 AM, Stephen wrote:
>> Thanks, I am quite pleased how it turned out.
>
>
> I'm not so pleased with the Dragon Lady.
>
> This is the best I could do with this model. I can't get rid of the
> stripes. :(
>
> Two days, 19 df3s and umpteen gigabytes later.
>
> But then the books said.
> "They were, he realized, as eye-unsettling as pictures on a
> three-dimensional postcard—with the same striatums hanging, like a
> screen, just before, or was it just behind them."
>

I am a bit puzzled by the stripes and not sure what might generate them. 
I suppose you have tried subdividing the model further before generating 
the df3? It has been a while since I did this exercise...

On the other hand, the book is clear indeed about this so it is acceptable.


-- 
Thomas


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From: Stephen
Subject: Re: A Dahlgren Projector.
Date: 3 Aug 2016 06:52:07
Message: <57a1ccd7$1@news.povray.org>
On 8/3/2016 7:51 AM, Thomas de Groot wrote:
> I am a bit puzzled by the stripes and not sure what might generate them.

There are two types. One caused by the sectioning of the model. The 
others look like gaps.

> I suppose you have tried subdividing the model further before generating
> the df3? It has been a while since I did this exercise...
>
No I've not. The obj file itself is 12k in size and has 78000 vertexes 
and 144500 faces.
I am rendering the TGAs at 512 by 512 with 512 slices. I will try 
reducing the number if slices to see if that makes any difference.
It is irritating that PovRay takes about 14 seconds to do a save.

> On the other hand, the book is clear indeed about this so it is acceptable.

For 1975 when the book was published. I would like to do better if I can.
I have a couple of other dragons I can try but they are all thin.

-- 

Regards
     Stephen


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From: Thomas de Groot
Subject: Re: A Dahlgren Projector.
Date: 3 Aug 2016 07:33:12
Message: <57a1d678@news.povray.org>
On 3-8-2016 12:52, Stephen wrote:
> On 8/3/2016 7:51 AM, Thomas de Groot wrote:
>> I am a bit puzzled by the stripes and not sure what might generate them.
>
> There are two types. One caused by the sectioning of the model. The
> others look like gaps.
>
>> I suppose you have tried subdividing the model further before generating
>> the df3? It has been a while since I did this exercise...
>>
> No I've not. The obj file itself is 12k in size and has 78000 vertexes
> and 144500 faces.
> I am rendering the TGAs at 512 by 512 with 512 slices. I will try
> reducing the number if slices to see if that makes any difference.
> It is irritating that PovRay takes about 14 seconds to do a save.

Hmmm. My tests with a Poser head and a Poser skeleton in 2013 were obj 
files of several MBs: 2.3 for the head and 34.5 for the skeleton, so 
that is another kettle of fish entirely. I really think you will need a 
more accurate model.

>
>> On the other hand, the book is clear indeed about this so it is
>> acceptable.
>
> For 1975 when the book was published. I would like to do better if I can.
> I have a couple of other dragons I can try but they are all thin.
>

That is indeed true.


I am making progress on the view of Bellona. The bridge is about 
finished although details are needed and a better render of the 
atmosphere. Coming soon.

-- 
Thomas


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From: Stephen
Subject: Re: A Dahlgren Projector.
Date: 3 Aug 2016 10:09:09
Message: <57a1fb05@news.povray.org>
On 8/3/2016 12:33 PM, Thomas de Groot wrote:
> On 3-8-2016 12:52, Stephen wrote:

> Hmmm. My tests with a Poser head and a Poser skeleton in 2013 were obj
> files of several MBs: 2.3 for the head and 34.5 for the skeleton, so
> that is another kettle of fish entirely. I really think you will need a
> more accurate model.

Oops 12 Meg. :)

>
>
> I am making progress on the view of Bellona. The bridge is about
> finished although details are needed and a better render of the
> atmosphere. Coming soon.
>

We will need to check compatibility of the media.
I have everything in one big file. (That is how B3D works.) When I am 
satisfied it's as good as I can get it I will split it into include files.

I am posing a Chinese Dragon to see how that behaves.



-- 

Regards
     Stephen


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