POV-Ray : Newsgroups : povray.advanced-users : focal_point with camera transform? : Re: focal_point with camera transform? Server Time
31 Oct 2024 19:46:52 EDT (-0400)
  Re: focal_point with camera transform?  
From: Andy
Date: 9 Nov 2013 18:05:00
Message: <web.527ebf289915e2734dc349de0@news.povray.org>
Alain <kua### [at] videotronca> wrote:

> >
> >> camera {
> >>   perspective
> >>   angle 60
> >>
> >>   location<0,7,7>
> >>   look_at<0,0,-1>
> >>
> >>   focal_point <0.0,3.5,1>
> >>          aperture 0.5
> >>          blur_samples 100
> >>          confidence .9
> >>          variance 1/10000
> >> }
> >>
> >> Then I do this, and it doesn't work:
> >> camera {
> >>   perspective
> >>   direction <0,0,-1>
> >>   angle 60
> >>
> >>   transform { matrix<1,0,0,0,1,0.1,0,-0.1,1,0,-1.75,-12> inverse }
> >>
> >>   focal_point <0.0,3.5,1>
> >>          aperture 0.5
> >>          blur_samples 100
> >>          confidence .9
> >>          variance 1/10000
> >> }
> >>
> >> The reason why I am using direction with z negative is because I am using OpenGL
> >> to generate the matrix, where Z goes towards the camera, not away.
> >
> >
> > As soon as i wrote "Where Z goes towards the camera, not away." and hit "enter",
> > it hit me.
> >
> > In the matrix above, i am translating -12 on the Z. Since direction is set to be
> > negative, I need to compensate for that by changing this:
> >
> > focal_point <0.0,3.5,1>
> >
> > to this:
> >
> > focal_point <0.0,3.5,-11>
> >
> > -12-11=1, and 1 is where i want the focal point to be set up on Z.
> >
> > It seems to work? Am I heading down the right path?
> >
> >
> >
> >
> Try defining your camera without focal blur and only add it after the
> transform.
>
> Normaly, focal_point define an absolute location relative to the origin
> of the coordinate system.

Would it help if I uploaded the POV file?  Here is what I am working with:
http://www.heinleins.com/library.pov.zip


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