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17 Aug 2024 08:18:52 EDT (-0400)
  Sphere Questions (Message 1 to 5 of 5)  
From: Hershel Robinson
Subject: Sphere Questions
Date: 28 Oct 2001 11:22:55
Message: <3bdc30df@news.povray.org>
After looking at everyone else's stuff for some time now, I have decided to
make my first post to this group.  (Don't be afraid to bash my image,
however--my own brother doesn't think much of it.)

This is a WIP.  The rings and the spheres are symbolic (what exactly they
represent is a long story and not terribly important).

I have a few questions about the spheres:
1 The right one (even in my PPM file) appears to be out of focus.
2 The middle one seems slightly larger than its neighbors, but I am guessing
that's just because it is of a lighter color than they are.
3 The right-most one, however, appears to be significantly larger than it
should be.  Is this also just because of the color contrast or I am doing
something wrong?

Thanks,
Hershel Robinson

PS: For anyone interested, the mountains are generated by gforge.


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From: Ib Rasmussen
Subject: Re: Sphere Questions
Date: 28 Oct 2001 11:44:35
Message: <3BDC36A6.808E3A08@ibras.dk>
Hershel Robinson wrote:

> I have a few questions about the spheres:
> 1 The right one (even in my PPM file) appears to be out of focus.
> 2 The middle one seems slightly larger than its neighbors, but I am guessing
> that's just because it is of a lighter color than they are.
> 3 The right-most one, however, appears to be significantly larger than it
> should be.  Is this also just because of the color contrast or I am doing
> something wrong?

You are getting wideangle distortion. You can see it on the squares too.
Move the camera back, and narrow the camera angle to compensate.

/Ib


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From: ingo
Subject: Re: Sphere Questions
Date: 28 Oct 2001 11:46:41
Message: <Xns9148B4D993548seed7@povray.org>
in news:3bdc30df@news.povray.org Hershel Robinson wrote:

> I have a few questions about the spheres:
> 1 The right one (even in my PPM file) appears to be out of focus.

It is not, That you see it like that may be the result of the texture 
that has less sharp color changes than the neighbour spheres.

> 2 The middle one seems slightly larger than its neighbors, but I am
> guessing that's just because it is of a lighter color than they
> are. 

Yes, probably due to its brightness.

>3 The right-most one, however, appears to be significantly
> larger than it should be....

Yes, because of its 'deformation'. 
Look at http://www.students.tut.fi/~warp/povVFAQ/misconceptions.html
The item - Perspective doesn't affect a sphere


Ingo

-- 
Photography: http://members.home.nl/ingoogni/
Pov-Ray    : http://members.home.nl/seed7/


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From: F Audet
Subject: Re: Sphere Questions
Date: 28 Oct 2001 15:22:24
Message: <3BDC6817.99F00AAD@sympatico.ca>
>
> 3 The right-most one, however, appears to be significantly larger than it
> should be.  Is this also just because of the color contrast or I am doing
> something wrong?

I think that what is making the right-most sphere appear larger is simply
the angle of your camera...  The wider the angle,  the larger the
distortion of the perspective.

Alex Pilot


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From: Dan Johnson
Subject: Re: Sphere Questions
Date: 28 Oct 2001 15:51:10
Message: <3BDC7021.B832E131@hotmail.com>
Hershel Robinson wrote:
> 
> After looking at everyone else's stuff for some time now, I have decided to
> make my first post to this group.  (Don't be afraid to bash my image,
> however--my own brother doesn't think much of it.)
 
Whenever I feel I feel inadequate with Povray I look at Gilles Tran's
early image.  Look at his post My 3rd povray pic ever posted 4/20/99. 
Then marvel at his IRTC winners.  
-- 
Dan Johnson 

http://www.geocities.com/zapob


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