>Jean Montambeault <jrm### [at] videotronca> wrote:
>:>>  camera
>:>>  { location -z*Distance
>:>>  look_at 0
>:>>  rotate CameraRotation
>:>>  translate ObjectCenter
>:>>  }
>
>:     That rotation with Camera_Rotation that you're suggesting...
Okay,
>: let's try it : first you carefully set a Distance : fine until now.
>: Second you rotate along the azimuth, something like "rotate
y*Azimuth"
>: (note that you won't be able to use one single vector as the
rotation
>: would happen about the X axis first, then the Y axis... and you
want
>: more control than that) : hey ! everything is fine, the distance
about
>: the origin is the same and we're on the side of the object that we
>: want. Yeah ! But now, how do you go about getting some altitude
>: (positive or negative) ?
>
>  Easyly. You first rotate around the X axis to the the altitude and
then
>around the Y axis to get the direction where we are looking from.
Like this:
>  camera
>  { location -z*Distance
>    look_at 0
>    rotate x*Latitude rotate y*Longitude

        You're right for that. I should have seen it.

>    translate ObjectCenter

     Here, if you translate that way again, your camera will land in
the middle of your object, won't it ? If I use your method for
positionning the camera how do I extract the information about the
vector where it is sitting then ? I need to add it to ObjectCenter to
keep the same relative point of vue relative to the object. Is there a
function in POV that will return such a vector ? Of course, it can be
found by trigonometric calculation but then why bother rotating and
not position the camera by that mean right from the beginning ?

    If not...well, I've learned lately that one can make a union of
any object in a scene, even if they don't share any space. So I guess
that one could make a union of all there is in the scene, find the
coordinates of the point of interest, translate while reversing the
signs on the x, y and z values in it so it finds itself at the origin
point rotate the camera at will using your method and once finished
put it back in place... I find no major reason for not doing it that
way if it remains transparent always. Would it ?

    Thanks anyway for answering. I understand that for experienced
POVists this subject is not as sexy as NURBS, infinite loopings and 4D
sponging but it is to me. I like my solution because it is elegant ( 5
lines of script )and powerful like when making lighting or clipping
camera dependent. I guess that flybys would be easier if moving the
camera rather than a whole world but I'm not quite to that level yet.
It models reality which is always more user friendly.

        If you feel like getting an idea of what I'm aiming at you can
download those .AVI's at

    http://pages.infinit.net/copeau/clips01mini.AVI

    http://pages.infinit.net/copeau/Calyps01.AVI

        They are 300 kB and 400 kB or so.

        Thanks again.

            Jean




>
>
>--
>main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[
i]
>):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*-
Warp -*/

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