POV-Ray : Newsgroups : povray.general : Straight-on wide camera Server Time
6 Nov 2024 22:15:31 EST (-0500)
  Straight-on wide camera (Message 1 to 6 of 6)  
From: leming
Subject: Straight-on wide camera
Date: 15 Jun 2002 23:15:53
Message: <3D0C0233.7050902@spamthis.com>
I need a camera that will be able to render to a wide image (say 
400x100) and not have any distortions, just be straight-on to the image. 
Is there a setting to do this?  Appologies if my description isn't very 
good.

I have been playing with the various projection types, and haven't been 
able to find one that does what I'm looking for, or possibly I have just 
blindly skipped over what I need.
--
Kevin


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From: Christopher James Huff
Subject: Re: Straight-on wide camera
Date: 15 Jun 2002 23:24:36
Message: <pan.2002.06.15.22.24.59.596412.1173@mac.com>
On Sat, 15 Jun 2002 23:12:51 -0500, leming wrote:

> I need a camera that will be able to render to a wide image (say
> 400x100) and not have any distortions, just be straight-on to the image.
> Is there a setting to do this?  Appologies if my description isn't very
> good.

To render at that aspect ratio, try setting right to x*1 and up to y*0.25.
For the no distortion, including perspective distortion, you need an
orthographic camera. This means the camera rays will be parallel, not
spreading out as with the other types, but you will need to size the right
and up vectors to the desired camera view area, just keep them in a 4/1
ratio.


-- 
Christopher James Huff <chr### [at] maccom>
POV-Ray TAG e-mail: <chr### [at] tagpovrayorg>
WWW: http://homepage.mac.com/chrishuff/


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From: Slime
Subject: Re: Straight-on wide camera
Date: 16 Jun 2002 00:38:03
Message: <3d0c162b$1@news.povray.org>
> For the no distortion, including perspective distortion, you need an
> orthographic camera.

Well, that depends on what kind of distortion, or what you're considering
"distortion" to be. You might find that a vertical cylindrical camera works
well, or maybe a panoramic one. Whatever kind you use, it's important to set
up the camera so that it matches the image's aspect ratio, to avoid
stretching.

 - Slime
[ http://www.slimeland.com/ ]


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From: Warp
Subject: Re: Straight-on wide camera
Date: 16 Jun 2002 11:39:32
Message: <3d0cb133@news.povray.org>
AFAIK ultra_wide_angle and panoramic are precisely designed for very wide
images. You should try them (try with different values for 'angle' until
it looks good).

-- 
#macro N(D)#if(D>99)cylinder{M()#local D=div(D,104);M().5,2pigment{rgb M()}}
N(D)#end#end#macro M()<mod(D,13)-6mod(div(D,13)8)-3,10>#end blob{
N(11117333955)N(4254934330)N(3900569407)N(7382340)N(3358)N(970)}//  - Warp -


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From: leming
Subject: Re: Straight-on wide camera
Date: 16 Jun 2002 16:37:56
Message: <3D0CF648.3070702@spamthis.com>
Warp wrote:
>   AFAIK ultra_wide_angle and panoramic are precisely designed for very wide
> images. You should try them (try with different values for 'angle' until
> it looks good).
> 

I have tried both ultra_wide_angle and panoramic, and personally I dont 
like playing with the angle value trying to find what looks good, its a 
waste of time. But the orthographic with the right and up values seems 
to work good, I just have to narrow down the values so it fits how it 
needs to. But otherwise, its what I was looking for with the parallel 
rays instead of originating from a point, before I didn't know about 
changing the up and right values like that (dont think its mentioned in 
the manual, and I've never used orthographic before).

All in all, thanks everyone.
--
Kevin


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From: leming
Subject: Re: Straight-on wide camera
Date: 17 Jun 2002 01:32:17
Message: <3D0D7386.2020905@spamthis.com>
Christopher James Huff wrote:
> To render at that aspect ratio, try setting right to x*1 and up to y*0.25.
> For the no distortion, including perspective distortion, you need an
> orthographic camera. This means the camera rays will be parallel, not
> spreading out as with the other types, but you will need to size the right
> and up vectors to the desired camera view area, just keep them in a 4/1
> ratio.

Just on a final note to this thread, for anyone using it now or in the 
future as reference, the aspect ratio is right:up, so since mine was 
400x100, a 4:1 ratio, it was right x*4; up y*1, and then I have modified 
those to get the proper "zoom" of the camera, but the ratio must be kept 
4:1, so it can be modified to say, 100:25.
--
Kevin


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