POV-Ray : Newsgroups : povray.newusers : 1 vanishing point perspective Server Time: 29 Jan 2020 15:01:10 GMT
  1 vanishing point perspective (Message 1 to 8 of 8)  
From: kurtz le pirate
Subject: 1 vanishing point perspective
Date: 3 Jan 2020 09:50:14
Message: <5e0f0e56$1@news.povray.org>
Hello.

What are the camera settings that can be used to make these kinds of 
perspectives ?

One sample here 
<http://www.graphit-marker.com/blog-en/grilles-de-perspective/> @ 
Frontal perspective â 1 vanishing point

Not found help at 
<https://www.povray.org/documentation/3.7.0/r3_4.html#r3_4_2_2> :(




-- 
Kurtz le pirate
Compagnie de la Banquise


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From: Thomas de Groot
Subject: Re: 1 vanishing point perspective
Date: 3 Jan 2020 11:55:57
Message: <5e0f2bcd$1@news.povray.org>
Op 03/01/2020 om 10:50 schreef kurtz le pirate:
> Hello.
> 
> What are the camera settings that can be used to make these kinds of 
> perspectives ?
> 
> One sample here 
> <http://www.graphit-marker.com/blog-en/grilles-de-perspective/> @ 
> Frontal perspective â 1 vanishing point
> 
> Not found help at 
> <https://www.povray.org/documentation/3.7.0/r3_4.html#r3_4_2_2> :(
> 
> 
> 
> 

I would say: the orthographic camera. I think paragraph 3.4.2.2.2 in the 
help is fairly straightforward. Sorry, I have no time presently to be 
more explicit and/or make a test.

-- 
Thomas


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From: Kenneth
Subject: Re: 1 vanishing point perspective
Date: 4 Jan 2020 17:15:00
Message: <web.5e10c74642dc78e1d98418910@news.povray.org>
[I've been away from the newsgroups for a long time; this is my first post in
quite awhile!]

I'm not a 'student' of perspective in drawing (although I like to sketch a lot),
but I would say that POV's regular perspective camera, in and of itself,
produces the kind of views you're looking for.

The 'perspective' camera doesn't introduce any curvilinear distortions, the way
a real camera lens would. (I think that's because it's essentially a 'pinhole
camera'.)

To my mind, the number of vanishing points in a scene seems to depend on the
camera's viewpoint (and maybe the particular subject matter in the scene?) Maybe
that's a VERY obvious statement, ha. If the camera is looking 'straight
ahead'--and all of the scene objects' surface planes are  parallel or
orthogonal(?) to the camera plane-- then it looks like "1-point perspective" to
me. (That's my naive analysis, anyway.)

Here's a really simple scene to experiment with. The appearence of the rotated
cube looks like... 2-point perspective?
-------

#version 3.7;
global_settings {assumed_gamma 1.0}
default{finish{ambient 1 diffuse 0}}

camera {
  perspective
  location  <1.7, 2.9, -4.2> // experiment with these settings
  look_at   <1.7, 2.9, 0>
  right     x*image_width/image_height
  angle 80 // a very wide-angle view, just to show the results
}

background{rgb .1}

plane{y,0
     no_shadow
         pigment{
                checker
                rgb <1,0,0>
                rgb 0
                scale 4
                }
         }

box{0,2
 pigment{checker scale .25}
 rotate 45*y
 translate 1.5*x
 }

difference{
box{0,5 translate <-2.5,0,-2.5>}
box{0,4.5 translate <-2.25,.25,-3.0>}
pigment{
   average
   pigment_map{
        [1 gradient z
            frequency 2
            color_map{
                  [.5 rgb .1]
                  [.5 rgb 1]
                     }
        ]
        [1 gradient y
            frequency 2
            color_map{
                  [.5 rgb .1]
                  [.5 rgb 1]
                     }
        ]
             }

             translate -.001
        }
        translate <1,0,3>
        }


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From: Kenneth
Subject: Re: 1 vanishing point perspective
Date: 4 Jan 2020 17:20:01
Message: <web.5e10c8f442dc78e1d98418910@news.povray.org>
"Kenneth" <kdw### [at] gmailcom> wrote:

> If the camera is looking 'straight
> ahead'--and all of the scene objects' surface planes are  parallel or
> orthogonal(?) to the camera plane-- then it looks like "1-point
> perspective" tome. (That's my naive analysis, anyway.)

.... AND all the horizontals and verticals in the scene remain so.


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From: Bald Eagle
Subject: Re: 1 vanishing point perspective
Date: 4 Jan 2020 23:50:01
Message: <web.5e1123dc42dc78e14eec112d0@news.povray.org>
"Kenneth" <kdw### [at] gmailcom> wrote:
> [I've been away from the newsgroups for a long time; this is my first post in
> quite awhile!]

Mr W!  My namesake!
Welcome back, old friend!  :)

I hope that everything IRL is going ... better.   You were absent, but not
forgotten.

I see that VA is going straight down the soil pipe, though VCDL and the general
citizenry is pushing back HARD.   I hope everything goes well in Richmond on Jan
20.

It's very good to see you again.


Bill


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From: kurtz le pirate
Subject: Re: 1 vanishing point perspective
Date: 5 Jan 2020 10:38:32
Message: <5e11bca8$1@news.povray.org>
On 04/01/2020 18:11, Kenneth wrote:
> [I've been away from the newsgroups for a long time; this is my first post in
> quite awhile!]
> 
> I'm not a 'student' of perspective in drawing (although I like to sketch a lot),
> but I would say that POV's regular perspective camera, in and of itself,
> produces the kind of views you're looking for.
> 
> The 'perspective' camera doesn't introduce any curvilinear distortions, the way
> a real camera lens would. (I think that's because it's essentially a 'pinhole
> camera'.)
> 
> To my mind, the number of vanishing points in a scene seems to depend on the
> camera's viewpoint (and maybe the particular subject matter in the scene?) Maybe
> that's a VERY obvious statement, ha. If the camera is looking 'straight
> ahead'--and all of the scene objects' surface planes are  parallel or
> orthogonal(?) to the camera plane-- then it looks like "1-point perspective" to
> me. (That's my naive analysis, anyway.)
> 
> Here's a really simple scene to experiment with. The appearence of the rotated
> cube looks like... 2-point perspective?

Thanks for that.

On my side and after several tries, I have arrived at what i want. The 
camera parameters are quite difficult to adjust.

camera {
  location <36,5,0>
  right x*image_width/image_height
  look_at <0,5,0>
  angle 45
  }

All the frames are identical. The red dot is at infinity on -x axis
See result image in p.b.i.




-- 
Kurtz le pirate
Compagnie de la Banquise


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From: Kenneth
Subject: Re: 1 vanishing point perspective
Date: 5 Jan 2020 21:20:01
Message: <web.5e1251fc42dc78e1d98418910@news.povray.org>
"Bald Eagle" <cre### [at] netscapenet> wrote:
>
> Mr W!  My namesake!
> Welcome back, old friend!  :)
>
Thanks Bill, much appreciated. I never forgot the ol' POV-Ray gang while I was
'away'. :-) Yeah, it's been long uphill climb, back to my usual self (whatever
that is!!) Financial problems and a 6-year relationship bust-up, plus some other
goodies-- all at the same time. :-/

I need to download the latest v3.8 alpha, to see what Clipka and the other
madmen have been cooking up since last... February! And I'm a little
out-of-practice with coding.


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From: Bald Eagle
Subject: Re: 1 vanishing point perspective
Date: 6 Jan 2020 23:55:01
Message: <web.5e13c7bf42dc78e14eec112d0@news.povray.org>
"Kenneth" <kdw### [at] gmailcom> wrote:

> Financial problems and a 6-year relationship bust-up, plus some other
> goodies-- all at the same time. :-/

Hark.  I hear an all too familiar story.
Sorry for your many and compounded woes. Here's hoping that you shake off all
the last of it and the doors that closed have freed you to walk through the ones
that will open.


> I need to download the latest v3.8 alpha, to see what Clipka and the other
> madmen have been cooking up since last... February! And I'm a little
> out-of-practice with coding.

Indeed.   Our clipka went MIA a while back and no one seems to know where he is
or what he is up to.  There have been some sporadic spurts of activity, some
inspirations, many roadblocks, and a few new faces as well as some visits from
folks who haven't been around in years.


Hang in there,

Bill


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