Trail effect
Sorry for this bombardment of [probably stupid] questions this week, I'm
still getting to grips with all the jitter objects and the differences from
GEM that I used to use in PD.
What would be people's recommended methods to achieve the following be:
I'm trying to process live footage from a webcam (that is being keyed over
another video). I've already got it so that the background is removed
leaving only people in front of the camera. I now want to create an effect
where when people move around in front of the camera it leaves a trail of
images (say 500ms cam grabs) following them from where they were standing
before, that then take a set period of time to fade away. But the longer
they stand in one place, after they move the longer it takes for the images
to fade away.
I hope that is clear. It's difficult keeping that concise when there is such
a vivid image in my head of how this should look!
Any tips from you pros?! ;)
Thanks...again,
Jonathan
jit.slide will do.
Try making you own feedback system with different delays to get more
of the effect you're looking for. Here's an example using 3D buffers:
wes
wesley's suggestions are super, but if you want to stick to jit.slide you
should convert matrix going into jit.slide to float32 type for better
accuracy/longer trail effects.
also, you could go to www.maxobjects.com and search for cv.jit.mean object
cheers,
nesa
I'm I right in thinking that I should make this conversion by adapting the
incoming matrix object as so: [jit.matrix 4 char float32 320 240] ? Because
this is causing the final image to end us as big lines moving up and down
the window!
Cheers
Jonathan
P.S. Is there an overall intro guide to Jitter I can read somewhere so I
don't have to keep asking you guys these annoying questions?
On Apr 22, 2006, at 4:19 PM, nesa wrote:
> wesley's suggestions are super, but if you want to stick to
> jit.slide you should convert matrix going into jit.slide to float32
> type for better accuracy/longer trail effects.
You can also get longer trails without converting to float by using
jit.wake (which keeps a high resolution feedback buffer).
-Joshua
almost, you should use float32 instead of char:
jit.matrix 4 float32 320 240
checkout jit.matrix help file.
but, joshua gave you another idea in another post. i knew there was
something, but couldn't remember: my mind just kept gloping, gloping,
gloping instead of waking...
best,
nesa
Got there just before you had to save me Nesa!
Thanks everybody for the help on this, converting to float32 has done
exactly what I wanted, the feedback can now remain on screen for upwards of
10mins as I wanted.
Jonathan
ok, but please try joshua's suggestion, jit.wake, maybe you'll find use of
its other functions.
best,
nesa
I did try jit.wake, and I liked the effects it produced, especially the soft
saturated look. But I couldn't produce the longer time effects with it that
I needed. But it's still another object I know for the future!
I actually LOVE the jit.wake object. It looks so pretty...
> P.S. Is there an overall intro guide to Jitter I can read somewhere so I
> don't have to keep asking you guys these annoying questions?
>
Yup, the Jitter tutorials in the documentation
(https://cycling74.com/downloads/jitter). Browsing through
examples/jitter-examples/ can also give you a good idea what Jitter is
capable of.
best,
dan