POV-Ray : Newsgroups : povray.general : What is this??? Server Time
1 Nov 2024 21:22:09 EDT (-0400)
  What is this??? (Message 1 to 8 of 8)  
From: Rune S  Johansen
Subject: What is this???
Date: 14 Jul 1999 07:25:32
Message: <378c73ac@news.povray.org>
If you render the code below you will see a weird phong highlight.

I would have expected a ring-formed phong highlight, but this appears.

camera {
   location y/10
   look_at 0
}

light_source {100*y, color 1}

plane {
   y, 0
   pigment {color 0}
   normal {onion 1.5}
   finish {ambient 0 diffuse 0 phong 1 phong_size 300}
}

Why does it look like that?

Greetings,

Rune S. Johansen

---
Visit The RSJ Website at http://welcome.to/rsj
for 3D images including still lives, dragons,
mathematical shapes, and more. Stereograms,
tutorials, The POV Desktop Theme, all the jokes
"you know you have been raytracing too long when",
miscellaneous other things, and a lot of fun!


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From: Ken
Subject: Re: What is this???
Date: 14 Jul 1999 07:32:06
Message: <378C7412.34B32EBD@pacbell.net>
"Rune S. Johansen" wrote:
> 
> If you render the code below you will see a weird phong highlight.
> 
> I would have expected a ring-formed phong highlight, but this appears.
> 
> camera {
>    location y/10
>    look_at 0
> }

Try your camera location at y*10 and you get what you expect.

-- 
Ken Tyler
  
mailto://tylereng@pacbell.net
http://home.pacbell.net/tylereng/links.htm


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From: Rune S  Johansen
Subject: Re: What is this???
Date: 14 Jul 1999 07:38:08
Message: <378c76a0@news.povray.org>
Ken wrote:
>"Rune S. Johansen" wrote:
>>
>> If you render the code below you will see a weird phong highlight.
>>
>> I would have expected a ring-formed phong highlight, but this appears.
>>
>> camera {
>>    location y/10
>>    look_at 0
>> }
>
>Try your camera location at y*10 and you get what you expect.

I know, but what is THIS?

Working with the cd include file, I have to know how phong highlights work.
And I don't understand this.

Greetings,

Rune S. Johansen

---
Visit The RSJ Website at http://welcome.to/rsj
for 3D images including still lives, dragons,
mathematical shapes, and more. Stereograms,
tutorials, The POV Desktop Theme, all the jokes
"you know you have been raytracing too long when",
miscellaneous other things, and a lot of fun!

>Ken Tyler
>
>mailto://tylereng@pacbell.net
>http://home.pacbell.net/tylereng/links.htm


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From: Mike
Subject: Re: What is this???
Date: 14 Jul 1999 10:51:08
Message: <378CA219.7F5C1803@aol.com>
It seems to be a by-product of ramp_wave.  Adding sine_wave makes it
disappear, but there also seems to some strange things happening with
onion near the origin.  I found something really cool trying this out
though.  Check this out:

camera {
   location <0, .01, 0>
   look_at 0
}

light_source {100*y, color 1}

plane {
   y, 0
   pigment {color 0}
   normal {onion 1.5 sine_wave}
   finish {ambient 0 diffuse 0 phong 1 phong_size 300}
}

Oh, and render this one big and stare at it for about a minute. :)

camera {
   location <0, 20, 0>
   look_at 0
}

light_source {100*y, color 1}

plane {
   y, 0
   pigment {color 0}
   normal {onion 1.5 sine_wave}
   finish {ambient 0 diffuse 0 phong 1 phong_size 10}
}

While you are looking at it, think about this - You are getting very
sleepy...your eyelids are getting heavy...when you awaken you will cluck
like a chicken.

-Mike


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From: Uwe Zimmermann
Subject: Re: What is this???
Date: 14 Jul 1999 10:57:34
Message: <378CA55E.4CFCFA77@ele.kth.se>
"Rune S. Johansen" wrote:
> 
> If you render the code below you will see a weird phong highlight.
> I would have expected a ring-formed phong highlight, but this appears.
> Why does it look like that?

What you can see there is the Ghost of POV - rotated by 90 degrees
clockwise. You can clearly see the eyes, nose and mouth...

Uwe.


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From: Ken
Subject: Re: What is this???
Date: 14 Jul 1999 11:00:33
Message: <378CA4D3.A4EE053@pacbell.net>
"Rune S. Johansen" wrote:

> I know, but what is THIS?
> 
> Working with the cd include file, I have to know how phong highlights work.
> And I don't understand this.
> 
> Greetings,
> 
> Rune S. Johansen

Try thinking in 3D instead of 2D and it MAY make sense. I think it is the
pattern converging from all three directions and you since your camera
is not quite at the origin you are seeing the edges of all three patterns
at once. If you camera were at the origin you would see a solid dot instead
of the three open spaces like you see in your example with the camera at
y*.1.

-- 
Ken Tyler
  
mailto://tylereng@pacbell.net
http://home.pacbell.net/tylereng/links.htm


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From: Ken
Subject: Re: What is this???
Date: 14 Jul 1999 11:01:59
Message: <378CA529.1011B9B3@pacbell.net>
Mike wrote:
> 
> It seems to be a by-product of ramp_wave.  Adding sine_wave makes it
> disappear, but there also seems to some strange things happening with
> onion near the origin.  I found something really cool trying this out
> though.  Check this out:
<snip>
> While you are looking at it, think about this - You are getting very
> sleepy...your eyelids are getting heavy...when you awaken you will cluck
> like a chicken.
> 
> -Mike

I really like the way it looks with the triangle wave too. Yawn !

-- 
Ken Tyler
  
mailto://tylereng@pacbell.net
http://home.pacbell.net/tylereng/links.htm


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From: Martin Crisp
Subject: Re: What is this???
Date: 15 Jul 1999 22:25:36
Message: <378e9820@news.povray.org>
Mike wrote in message <378CA219.7F5C1803@aol.com>...
[snip]

>While you are looking at it, think about this - You are getting very
>sleepy...your eyelids are getting heavy...when you awaken you will
cluck
>like a chicken.

hmm, take a sphere, put the default hexagon pattern (red, green, blue)
on it.

animate the sphere rotating in place (rotating around 2 axes works best)
animate the texture along it's z-axis so that in a cyclic animation it
translates exactly one pattern distance. [300 frames at 24fps works
well]

Take a 1960's sugar cube, sit back & wait

Have Fun
Martin
--
<Spa### [at] tesseractcomau> is a valid address
If you prefer mnemonic addresses you can use:
<Martin 'at' tesseract.com.au> or <Martin.Crisp 'at' Tourism.tas.gov.au>

My opinions should not be taken as indicative of Tourism Tasmania's
opinions


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