POV-Ray : Newsgroups : moray.win : AniPlugin Feature Request: Cyclic animations Server Time
28 Jul 2024 16:32:40 EDT (-0400)
  AniPlugin Feature Request: Cyclic animations (Message 1 to 2 of 2)  
From: Florian Fischer
Subject: AniPlugin Feature Request: Cyclic animations
Date: 27 Feb 2000 14:41:28
Message: <38B97DFD.F2D88545@gmx.de>
I think that someone mentioned this point before, but I'd like to
discuss this subject more precisely:
In POV-Ray, cyclic animation means that the last frame of the
animation is skipped, and the clock values calculated accordingly.
That's, however, only the one point, but when introducing this in in
the AnimPlugin, the second and the second-last key have to be copied
too. (at least in cubic interpolation mode, but who'd use something
else?)

Example:
Let's imagine that you want to make a ball roll a circle. You'll need
four keys for this. One (first frame) at the start-position, another
about a third along the circle, the same for the third, and the fourth
(last frame of the animation) at the start-position again.
However, when you render this, you'll be disappointed, as the ball
doesn't roll along a circle, but along a raindrop-like shape.
That is, of course, as for the first and last cubic interpolation, one
of the three surrounding keys is missing and thus, the ball starts
straight.
The "cyclic animation" feature should imaginarily extend the animation
so that the second key can be copied behind the last one, and the same
for the second-last key, which has to be copied beore the first one.
Well, it could even copy the first key to the last frame
automatically, and leave the last frame out (what POV-Ray does too).

You'd get nice looping animations in no time then.

Please think about it!

    Florian


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From: Alexander Enzmann
Subject: Re: AniPlugin Feature Request: Cyclic animations
Date: 29 Feb 2000 08:24:37
Message: <38BBC897.2C372BE4@mitre.org>
Florian Fischer wrote:
> 
> I think that someone mentioned this point before, but I'd like to
> discuss this subject more precisely:
> In POV-Ray, cyclic animation means that the last frame of the
> animation is skipped, and the clock values calculated accordingly.
> That's, however, only the one point, but when introducing this in in
> the AnimPlugin, the second and the second-last key have to be copied
> too. (at least in cubic interpolation mode, but who'd use something
> else?)

What you are looking for is along the lines of the Out of Range Types
(ORT's) that Max has.  I agree that sort of flexibility is very
important.  Note that there are quite a few ways you might want the
cycle to be interpolated (ping-pong is just as popular as repetition).

Quite a bit if UI work and coding has to be completed to get there. 
Keep hanging in there (and feel free to give me suggestions).

Xander


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