POV-Ray : Newsgroups : povray.tools.general : Norbert Kern's 'Position-Finder' code-- redux : Re: Norbert Kern's 'Position-Finder' code-- redux Server Time
8 Feb 2023 09:10:21 EST (-0500)
  Re: Norbert Kern's 'Position-Finder' code-- redux  
From: Kenneth
Date: 19 Sep 2018 16:30:00
Message: <web.5ba2b12fbb085d6ca47873e10@news.povray.org>
"Kenneth" <kdw### [at] gmailcom> wrote:

>
> *The code seems to be more precise if, for cam_ang, you use more of a 'zoom'
> angle than a wide-angle (i.e., 30 is better than 67, for example.) This would
> just be temporary, until the new object is correctly placed and you no longer
> need the macro.
>

Hmm. The 2nd part of that little paragraph needs clarifying (only because the
code is presently a self-contained test scene): The accurate placement of an
object *depends* on the camera angle (cam_ang) staying the same. It needs to be
pre-set with whatever value you choose, and NOT changed (at least *while* using
the macro). For example, with a given set of...

cam_loc
lookat
cam_ang

....for the camera, the preview render will look the way you want, and you then
choose a 'point of interest' in the scene. If you then *change* cam_angle, that
chosen point will not be where you thought it would be-- since the essence of
the code is to work solely with the visual on-screen preview (which 'sets' the
point of interest BASED ON the three parameters.) A different cam_angle would
naturally create a different-looking on-screen preview.

Again, this caveat applies only to the current test scene set-up.

BTW, you CAN currently use the macro itself in one of your own scenes, to try it
out. Just make sure the three camera parameters match those of the 'real' camera
in your scene. (And the macro call needs to go somewhere AFTER your own scene
camera; the macro's built-in camera temporarily replaces it.) Once you've placed
your new object, you no longer need the macro, and you can then change your own
camera parameters to whatever you like.


Post a reply to this message

Copyright 2003-2021 Persistence of Vision Raytracer Pty. Ltd.