I am trying to do an animation, a fly through. This is nothing complicated.
I want to move from one point higher and out further to a point closer to
the origin along a straight line. If I render just a single first scene, it
looks fine. The camera observes the look_at vector just fine. When I render
another single image with the camera repositioned at the end point again
the look_at vector is treated properly. The look_at point does not change
during the entire animation. My translation for the animation works except
the look_at point is not adjusted as the camera's point of view drops lower
in the scene.

I've been looking for another message with info on something like this and
find information for following more complex paths thru the space, as along
a spline, but I didn't want to employ such a complex figure just yet. I am
sure this question has been asked before and so I apologize to the group
for my impatience and inability to turn up the proper info in a search.

Thanks for any info anyone may have.

Oh yeah, here's the camer I have set up...

  camera {
    location <0.50, 16.00, -29.00>
    look_at  <1.0, 1.5, 2 >
    translate <0.0, -0.175*(10*clock), +0.125*(10*clock)>
  }

Raffles

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hmm. not sure about this maybe try this (untested):

camera {
     location <0.50, 16.00, -29.00>+<0.0, -0.175*(10*clock),
+0.125*(10*clock)>
     look_at  <1.0, 1.5, 2 >
   }

i guess when you declare the look_at value and afterwards reposition the
camera the look_at point moves with it.
but i can't figure out why the look_at point was proper in your former
renderings mentioned.

just my 2 cents
Roman



"Raffles" <nomail@nomail> wrote:
> I am trying to do an animation, a fly through. This is nothing complicated.
> I want to move from one point higher and out further to a point closer to
> the origin along a straight line. If I render just a single first scene, it
> looks fine. The camera observes the look_at vector just fine. When I render
> another single image with the camera repositioned at the end point again
> the look_at vector is treated properly. The look_at point does not change
> during the entire animation. My translation for the animation works except
> the look_at point is not adjusted as the camera's point of view drops lower
> in the scene.
>
> I've been looking for another message with info on something like this and
> find information for following more complex paths thru the space, as along
> a spline, but I didn't want to employ such a complex figure just yet. I am
> sure this question has been asked before and so I apologize to the group
> for my impatience and inability to turn up the proper info in a search.
>
> Thanks for any info anyone may have.
>
> Oh yeah, here's the camer I have set up...
>
>   camera {
>     location <0.50, 16.00, -29.00>
>     look_at  <1.0, 1.5, 2 >
>     translate <0.0, -0.175*(10*clock), +0.125*(10*clock)>
>   }
>
> Raffles

Post a reply to this message

Roman, thanks so much. I am rendering even as I write this and it appears to
be working.

You gave me something to think about because you question why the single
frame renderings I did of the start and ending frames looked correct. My
look at point at the starting point, is above the origin. So as the Y vector
decreases the look_at point becomes higher than the camera. The angle ought
to change but until your suggestion, it didn't. Thanks again for the idea
of summing the two vectors.

It does appear that the renderer does not recalculate the look_at point
during an animation run when the translate vector is separated from the
camera position vector. Combining them as you suggest is working!

Raffles

"Roman Reiner" <lim### [at] gmxde> wrote:
> hmm. not sure about this maybe try this (untested):
>
> camera {
>      location <0.50, 16.00, -29.00>+<0.0, -0.175*(10*clock),
> +0.125*(10*clock)>
>      look_at  <1.0, 1.5, 2 >
>    }
>
> i guess when you declare the look_at value and afterwards reposition the
> camera the look_at point moves with it.
> but i can't figure out why the look_at point was proper in your former
> renderings mentioned.
>
> just my 2 cents
> Roman
>
>
>
> "Raffles" <nomail@nomail> wrote:
> > I am trying to do an animation, a fly through. This is nothing complicated.
> > I want to move from one point higher and out further to a point closer to
> > the origin along a straight line. If I render just a single first scene, it
> > looks fine. The camera observes the look_at vector just fine. When I render
> > another single image with the camera repositioned at the end point again
> > the look_at vector is treated properly. The look_at point does not change
> > during the entire animation. My translation for the animation works except
> > the look_at point is not adjusted as the camera's point of view drops lower
> > in the scene.
> >
> > I've been looking for another message with info on something like this and
> > find information for following more complex paths thru the space, as along
> > a spline, but I didn't want to employ such a complex figure just yet. I am
> > sure this question has been asked before and so I apologize to the group
> > for my impatience and inability to turn up the proper info in a search.
> >
> > Thanks for any info anyone may have.
> >
> > Oh yeah, here's the camer I have set up...
> >
> >   camera {
> >     location <0.50, 16.00, -29.00>
> >     look_at  <1.0, 1.5, 2 >
> >     translate <0.0, -0.175*(10*clock), +0.125*(10*clock)>
> >   }
> >
> > Raffles

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