I finally had the time and inspiration to work on this again, and I think i've
nailed it.

I think I've managed to make the macro capable of handling animation for
multiple simultaneous emitters, but it needs testing.  It should work, in
theory.

Thoughts, suggestions?

Regards,
A.D.B.

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Attachments:
Download 'spraypaint.avi.dat' (410 KB)

Really cool! I had to watch it several times to see that the spray brush was
going up and down (as well as left to right)-- a nice realistic touch.

BTW, when I opened the video in Avidemux (my media viewer of choice), it gave me
this message:

"This video contains B-frames, but presentation time stamps (PTS) are either
missing or monotonically increasing [whatever THAT means!]. Avidemux can try to
reconstruct correct PTS by decoding the entire video. This may take a lot of
time. Proceed?"

(Hmm, "a lot of time"-- it took 3 seconds, ha.)

But I wonder if your .avi muxer is doing something weird or unintended?

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"Kenneth" <kdw### [at] gmailcom> wrote:
> Really cool! I had to watch it several times to see that the spray brush was
> going up and down (as well as left to right)-- a nice realistic touch.
>

In all honesty, that was necessary to get the paint to spread evenly, otherwise
it would be darker at the center.  I could also use a spiral path around the
outside, since it's a circular pattern anyway.

The pattern itself is provided by a pigment. In this case, I'm using an
image-map of the Aperture Science logo. (I'm making a note here: Huge Success!)

The path of the emitter is controlled by a pair of splines, it follows one,
while aiming at the other. The way this is built, it should also dovetail nicely
with my animation macros, but I haven't tried it yet. This animation took a
little over 26 hours to render, but I had to go back and redo the first 45
frames because I changed the color mid-render.

> BTW, when I opened the video in Avidemux (my media viewer of choice), it gave me
> this message:
>
> "This video contains B-frames, but presentation time stamps (PTS) are either
> missing or monotonically increasing [whatever THAT means!]. Avidemux can try to
> reconstruct correct PTS by decoding the entire video. This may take a lot of
> time. Proceed?"
>
> (Hmm, "a lot of time"-- it took 3 seconds, ha.)
>
> But I wonder if your .avi muxer is doing something weird or unintended?

I honestly have no idea, I just use mencoder in bash.  B frames appear to be
"prediction frames" containing only what's changed in the scene.  I have no idea
what causes the problem or how to fix it.

There appears to be a -correct-pts option, but the man page lists it as
experimental, and I know my version of ffmpeg is not up to date. I need to
upgrade my linux distro.

Anyway, glad you like it.

Regards,
A.D.B.

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hi,

"Kenneth" <kdw### [at] gmailcom> wrote:
> Really cool! I had to watch it several times to see that the spray brush was
> going up and down (as well as left to right)-- a nice realistic touch.

agree, good effect.  liked the stencil, would have liked to see how it's done.


> BTW, when I opened the video in Avidemux (my media viewer of choice), it gave me
> this message:
>
> "This video contains B-frames, but presentation time stamps (PTS) are either
> missing or monotonically increasing [whatever THAT means!]. Avidemux can try to
> reconstruct correct PTS by decoding the entire video. This may take a lot of
> time. Proceed?"
>
> (Hmm, "a lot of time"-- it took 3 seconds, ha.)
>
> But I wonder if your .avi muxer is doing something weird or unintended?

ouch.  runs perfectly fine here after renaming to drop the '.dat' (different
viewers on (three) separate machines).


regards, jr.

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"jr" <cre### [at] gmailcom> wrote:
> hi,
>
> "Kenneth" <kdw### [at] gmailcom> wrote:
> > Really cool! I had to watch it several times to see that the spray brush was
> > going up and down (as well as left to right)-- a nice realistic touch.
>
> agree, good effect.  liked the stencil, would have liked to see how it's done.
>
>
> > BTW, when I opened the video in Avidemux (my media viewer of choice), it gave me
> > this message:
> >
> > "This video contains B-frames, but presentation time stamps (PTS) are either
> > missing or monotonically increasing [whatever THAT means!]. Avidemux can try to
> > reconstruct correct PTS by decoding the entire video. This may take a lot of
> > time. Proceed?"
> >
> > (Hmm, "a lot of time"-- it took 3 seconds, ha.)
> >
> > But I wonder if your .avi muxer is doing something weird or unintended?
>
> ouch.  runs perfectly fine here after renaming to drop the '.dat' (different
> viewers on (three) separate machines).
>
>
> regards, jr.

See p.General for the macro.

Regards,
A.D.B.

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