POV-Ray : Newsgroups : povray.binaries.animations : camera position Server Time
20 Jul 2024 19:32:44 EDT (-0400)
  camera position (Message 1 to 7 of 7)  
From: rsibbald
Subject: camera position
Date: 18 Jul 2000 10:04:19
Message: <39746579.F0D584BE@julian.uwo.ca>
Is there any way to have pov return the camera's location values
throughout an
animation?  (yes it's me again and I thank all who've already tried to
help... I'll
try to explain better!)
What I want to do...
     I have a color coded scene which I would like to have the camera
travel around
(maybe on a spline but not for sure).  I also have a cylinder (legend)
which has the
range of colors from my scene on it.  I would like the legend to appear
in the animation
at all times.  Thus I figured I needed to know (at all times) the
position of the camera
as well as the camera's look_at value so I could have the legend
cylinder in between.

I hope I've done a better job of explaining, but if not let me know.

Thanks,
Rob


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From: Dave Blandston
Subject: Re: camera position
Date: 18 Jul 2000 10:36:38
Message: <39746b76@news.povray.org>
You can print the current value of a variable to the "Messages" screen
thusly:

#debug concat("\nThe current value of CameraX = ", str (CameraX, 0, 0),
".\r\n")

You can adjust the precision and number of decimal places shown by changing
the zeros. I hope this is what you mean...

-Dave


"rsibbald" <rsi### [at] julianuwoca> wrote in message
news:39746579.F0D584BE@julian.uwo.ca...
> Is there any way to have pov return the camera's location values
> throughout an
> animation?  (yes it's me again and I thank all who've already tried to
> help... I'll
> try to explain better!)
> What I want to do...
>      I have a color coded scene which I would like to have the camera
> travel around
> (maybe on a spline but not for sure).  I also have a cylinder (legend)
> which has the
> range of colors from my scene on it.  I would like the legend to appear
> in the animation
> at all times.  Thus I figured I needed to know (at all times) the
> position of the camera
> as well as the camera's look_at value so I could have the legend
> cylinder in between.
>
> I hope I've done a better job of explaining, but if not let me know.
>
> Thanks,
> Rob
>


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From: Marc-Hendrik Bremer
Subject: Re: camera position
Date: 18 Jul 2000 11:57:28
Message: <39747e68@news.povray.org>
No, I don't think so.

But how do you 'travel' the camera around? How do you determine where it is
looking at?

I can imagine two ways:

1. You compute the position (or let it compute by a .inc-file for the
spline). If you do, you will have a variable with the position.

2. You translate and rotate the camera. If you do, just do the same
transformations with your cylinder.

But I've the feeling that this was not what you wanted to know ;-)

Marc-Hendrik


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From: rsibbald
Subject: Re: camera position
Date: 18 Jul 2000 12:25:35
Message: <39748696.C59AA803@julian.uwo.ca>
Close...  tranlating and rotating the cylinder with the camera is exactly what
I want,
but the problem arises when I don't translate my "look_at" too, which I don't
want to
do.  The angle the camera takes will always be changing to accomodate the
'look_at'
thus even if the cylinder is always <0,5,5> ahead of the camera, it won't
always be
in the picture!


> 2. You translate and rotate the camera. If you do, just do the same
> transformations with your cylinder.
>
> But I've the feeling that this was not what you wanted to know ;-)
>
> Marc-Hendrik


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From: Marc-Hendrik Bremer
Subject: Re: camera position
Date: 18 Jul 2000 13:59:03
Message: <39749ae7@news.povray.org>
I see .... so your problem is, that due to the look_at you have an
extra-rotation of your camera, which you can't use easily for your cylinder.
Hm ... all I can think about is to re-compute the position of the camera
with the vector-transformation-functions of Pov (vrotate etc.) and use the
resulting vector to calculate the position of the cylinder.

Marc-Hendrik


rsibbald schrieb in Nachricht <39748696.C59AA803@julian.uwo.ca>...
>Close...  tranlating and rotating the cylinder with the camera is exactly
what
>I want,
>but the problem arises when I don't translate my "look_at" too, which I
don't
>want to
>do.  The angle the camera takes will always be changing to accomodate the
>'look_at'
>thus even if the cylinder is always <0,5,5> ahead of the camera, it won't
>always be
>in the picture!


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From: ryan constantine
Subject: Re: camera position
Date: 18 Jul 2000 15:38:32
Message: <3974B1F1.4A9CB81F@yahoo.com>
moray lets you bind both the camera's position and its look_at to
objects.  of course moray eventually outputs pov code, so there must be
some moray-povcode out there with this in it.  unfortunately, i've never
used those features so i don't have any laying around.

Marc-Hendrik Bremer wrote:
> 
> I see .... so your problem is, that due to the look_at you have an
> extra-rotation of your camera, which you can't use easily for your cylinder.
> Hm ... all I can think about is to re-compute the position of the camera
> with the vector-transformation-functions of Pov (vrotate etc.) and use the
> resulting vector to calculate the position of the cylinder.
> 
> Marc-Hendrik
> 
> rsibbald schrieb in Nachricht <39748696.C59AA803@julian.uwo.ca>...
> >Close...  tranlating and rotating the cylinder with the camera is exactly
> what
> >I want,
> >but the problem arises when I don't translate my "look_at" too, which I
> don't
> >want to
> >do.  The angle the camera takes will always be changing to accomodate the
> >'look_at'
> >thus even if the cylinder is always <0,5,5> ahead of the camera, it won't
> >always be
> >in the picture!


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From: Bob Hughes
Subject: Re: camera position
Date: 19 Jul 2000 15:48:30
Message: <3976060e@news.povray.org>
Okay, someone has made just such a thing accept it was originally for a
signature/logo.  Lewis
Sellers was the guy.  Should be posted to either the povray.binaries or text
scene-files group
about a year and a half ago or less.
Well, maybe I'm wrong.  Or partly wrong anyway.  Seems he has a PostTool utility to
add in a
previous image into the targa image frames.  http://www.public.usit.net/lsellers/ 
then the
Raytracing link there.
Oh, wait, I was right  (I'm looking as I type obviously).  Problem is I don't have
messages
going far enough back to know what the subject title is.

Bob


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