POV-Ray : Newsgroups : povray.newusers : Camera and horizontal viewing angle Server Time
29 Jul 2024 10:30:40 EDT (-0400)
  Camera and horizontal viewing angle (Message 1 to 9 of 9)  
From: vianagmo
Subject: Camera and horizontal viewing angle
Date: 21 Mar 2006 08:35:00
Message: <web.4420005c281f4029556862df0@news.povray.org>
Hi, everybody

I need an increment (a big one) in the horizontal viewing angle in my scene,
I am using orthographic camera_type, I have been tried with "angle", but I
need to preserve the size of my objects since I am working with exact
magnitudes, so like using "angle" modifies the size of my objects in the
rendering, this doesn't work for me. How can I get this?

Thanks.


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From: Warp
Subject: Re: Camera and horizontal viewing angle
Date: 21 Mar 2006 11:06:30
Message: <44202486@news.povray.org>
vianagmo <vaa### [at] unaleduco> wrote:
> I need an increment (a big one) in the horizontal viewing angle in my scene,
> I am using orthographic camera_type, I have been tried with "angle", but I
> need to preserve the size of my objects since I am working with exact
> magnitudes, so like using "angle" modifies the size of my objects in the
> rendering, this doesn't work for me. How can I get this?

  Do you mean you want to render with an aspect ratio wider than 4:3?

-- 
                                                          - Warp


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From: vianagmo
Subject: Re: Camera and horizontal viewing angle
Date: 21 Mar 2006 11:45:00
Message: <web.44202c54a59f6258556862df0@news.povray.org>
I have something like this:

camera
{
  orthographic
  location <0.0, 0.0, -250*mm>
  translate <(100*mm)*clock,0.0, 0.0>
  look_at <(100*mm)*clock, 0.0, 0.0>
}


I don't want to change the size of my objects (they have 780 X 780 px) in
the rendering but I need a big extension in the horizontal view, so they
never disappear  from the screen as the camera translates and preserve
their sizes. I thought that with the keyword "angle" I would solve this,
but the object appears much bigger or much smaller when I change this item,
so I don't know if there is a way to do what I want in POVRAY.


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From: Chris B
Subject: Re: Camera and horizontal viewing angle
Date: 21 Mar 2006 12:18:49
Message: <44203579$1@news.povray.org>
"vianagmo" <vaa### [at] unaleduco> wrote in message 
news:web.44202c54a59f6258556862df0@news.povray.org...
>I have something like this:
>
> camera
> {
>  orthographic
>  location <0.0, 0.0, -250*mm>
>  translate <(100*mm)*clock,0.0, 0.0>
>  look_at <(100*mm)*clock, 0.0, 0.0>
> }
>
>
> I don't want to change the size of my objects (they have 780 X 780 px) in
> the rendering but I need a big extension in the horizontal view, so they
> never disappear  from the screen as the camera translates and preserve
> their sizes. I thought that with the keyword "angle" I would solve this,
> but the object appears much bigger or much smaller when I change this 
> item,
> so I don't know if there is a way to do what I want in POVRAY.
>
>

Hi,

Still not exactly clear, but here's my guess. If you just want to get a 
wider rendered image without altering the size of the objects, you can set 
the aspect ratio of the orthographic camera based upon the image_width and 
image_height settings.

The following example sets the 'up' and 'right' vectors to do just that and 
can be rendered with different image widths (the width can be set as a 
command line option). The spheres should stay a constant size so long as the 
setting for the image height remains the same . If you change the image 
height then the size of the spheres will increase in proportion to the 
height. You can multiply the 'up' and 'right' vectors by a factor to adjust 
the object size at all if you need to.

Hope this helps,
Regards,
Chris B.

// Example command line options:    +H240 +W640  or  +H240 +W320  or  +H240 
+W5000

#local mm = 1;

camera
{
  orthographic
  location <0.0, 0.0, -250*mm>
  translate <(100*mm)*clock,0.0, 0.0>
  look_at <(100*mm)*clock, 0.0, 0.0>
  up    y
  right x * image_width/image_height
}

light_source { <-5,30,-10> 1 }
sphere {-x,0.5 pigment {color rgb <1,1,0>}}
sphere { 0,0.5 pigment {color rgb <1,1,0>}}
sphere { x,0.5 pigment {color rgb <1,1,0>}}


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From: Warp
Subject: Re: Camera and horizontal viewing angle
Date: 21 Mar 2006 12:51:59
Message: <44203d3f@news.povray.org>
Chris B <c_b### [at] btconnectcomnospam> wrote:
>   right x * image_width/image_height

  Be careful with using that. The drawbacks of that are described here:

http://tag.povray.org/povQandT/languageQandT.html#aspectratio

-- 
                                                          - Warp


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From: vianagmo
Subject: Re: Camera and horizontal viewing angle
Date: 21 Mar 2006 13:15:00
Message: <web.44204215a59f6258556862df0@news.povray.org>
Here is my complete code, and the command line I use is:

povray Test.ini +W1064 +H800  +ICilindros.pov


#declare mm=1.6;

#declare O11646016 =
cylinder
{
  <0,-10*mm,0>, <0, 10.0*mm, 0>, 10.0*mm
  texture
  {
    pigment
    {
      color <0.0, 0.0, 1.0>
    }
  }
}

object
{
  O11646016
  translate <0.0, 0.0, 5.0*mm>
  rotate <0.0, 0.0, 0.0>
}

#declare O11646176 =
cylinder
{
  <0, -5*mm, 0>, <0, 5.0*mm, 0>, 5.0*mm
  texture
  {
    pigment
    {
      color <0.0, 1.0, 0.0>
    }
  }
}

object
{
  O11646176
  translate <0.0, 0.0, -2.5*mm>
  rotate <0.0, 0.0, 0.0>
}


cylinder
{
  <0, 0, 0>, <0, 50.0*mm, 0>, 0.33*mm
  texture
  {
    pigment
    {
      color <1.0, 1.0, 1.0>
    }
  }
  rotate <0,0,-90>
  translate <-25*mm,25*mm,0>
}


cylinder
{
  <0, 0, 0>, <0, 50.0*mm, 0>, 0.33*mm
  texture
  {
    pigment
    {
      color <1.0, 1.0, 1.0>
    }
  }
  translate <-25*mm,-25*mm,0>
  rotate <0,0,90>
}


cylinder
{
  <0, 0, 0>, <0, 50.0*mm, 0>, 0.33*mm
  texture
  {
    pigment
    {
      color <1.0, 1.0, 1.0>
    }
  }
  translate <-25*mm,-25*mm,0>
}

cylinder
{
  <0, 0, 0>, <0, 50.0*mm, 0>, 0.33*mm
  texture
  {
    pigment
    {
      color <1.0, 1.0, 1.0>
    }
  }
  translate <25*mm,-25*mm,0>
}


camera
{
  orthographic
  location <0.0, 0.0, -250*mm>
  translate <(100*mm)*clock,0.0, 0.0>
  look_at <(100*mm)*clock, 0.0, 0.0>

}

global_settings
{
  ambient_light
  color <6.0, 6.0, 6.0>
}

Like you see I have the proportion of 1.33 (W/H) . Anyway, I included what
you say and change the command line, but the images still disappear from
the rendering window. I need that the bounding box (the slim cylinders)
have at least 780X780 pixels in (50mmX50mm) and that it completly appears in
each
rendering... Help Please!!!


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From: Chris B
Subject: Re: Camera and horizontal viewing angle
Date: 21 Mar 2006 14:21:16
Message: <4420522c@news.povray.org>
"vianagmo" <vaa### [at] unaleduco> wrote in message 
news:web.44204215a59f6258556862df0@news.povray.org...
> Here is my complete code, and the command line I use is:
>
> povray Test.ini +W1064 +H800  +ICilindros.pov
>
>   ... snip ...
>
> camera
> {
>  orthographic
>  location <0.0, 0.0, -250*mm>
>  translate <(100*mm)*clock,0.0, 0.0>
>  look_at <(100*mm)*clock, 0.0, 0.0>
> }
>
> ... snip ...
> Like you see I have the proportion of 1.33 (W/H) . Anyway, I included what
> you say and change the command line, but the images still disappear from
> the rendering window. I need that the bounding box (the slim cylinders)
> have at least 780X780 pixels in (50mmX50mm) and that it completly appears 
> in
> each
> rendering... Help Please!!!
>

I'm still not clear on what it is you need exactly, but if you use

  up    250*mm*y
  right 250*mm*x * image_width/image_height

and increase the width of your window to +W2000 you get what you seem to be 
asking for. Alternatively simply starting your camera 120mm further to the 
left (and adjusting the look_at point accordingly) satisfies your stated 
objective, as does moving the camera less in a full clock cycle.

You can also achieve the same without using the image_width and image_height 
settings by hand coding the values if you feel that the issues that Warp 
spotted may affect you.

If none of those do what you need, then maybe it would help for you to 
describe what you are trying to achieve in a more general way, or the 
purpose, or a little about the context or background of what you are trying 
to achieve.

Regards,
Chris B.


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From: Thorsten Froehlich
Subject: Re: Camera and horizontal viewing angle
Date: 21 Mar 2006 14:26:02
Message: <4420534a$1@news.povray.org>
> Like you see I have the proportion of 1.33 (W/H) . Anyway, I included what
> you say and change the command line, but the images still disappear from
> the rendering window. I need that the bounding box (the slim cylinders)
> have at least 780X780 pixels in (50mmX50mm) and that it completly appears in
> each
> rendering... Help Please!!!

Just use longer "up" and "right" vectors for the camera. The user manual 
explains the various camera parameters in detail in the tutorial as well as 
the reference sections. Start here, in particular with the "Up and Right 
Vectors" section: <http://www.povray.org/documentation/view/3.6.1/246/>

No other setting will get you want because you are using an orthographic 
camera, so there is no camera angle as there is no perspective projection.

	Thorsten


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From: vianagmo
Subject: Re: Camera and horizontal viewing angle
Date: 22 Mar 2006 10:10:00
Message: <web.44216802a59f6258556862df0@news.povray.org>
THANKS CHRIS AND THORSTEN!!!


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