Hi all,

I want to make some sort of slit scan patch, but I can't figure it out.

I now have a video loaded into pix_film and I have it masked by a line of 1px high. Then I copied this and did the same for another frame of the movie. I put in a translate object so I can move the first line above the second. But I'd have to do this a few hundred times, and thus I'd end up with a few hundred pix_film and texture objects. This makes the video verrrrrry sow. And that is of course not what I want. Is there any way I can do this in a better way?

To clarify, I took a screenshot (see attachment).

Greets,
Hans Willem

http://www.pdpatchrepo.info/hurleur/Picture_3.png

Okay, I tried pix_crop instead of an alphamask. It still slows down a lot, but less than before. If anybody knows a better way to do this, I'm all ears

Here's a few screenshots of what my patch produces:

Greets,
Hans Willem

looks interesting
i bet a many people would love to see it as an reusable abstraction

does it work in real time on a video stream?

Hi,

Here's the patch (attachment). Theoratically it can be modified to work on a live stream I guess, but at the moment it's way to slow...

http://www.pdpatchrepo.info/hurleur/crop_test.pd

more efficiant would be to map it on a obj object with the right texture coordinates assigned to fit your effect. you will need basic 3d skills and a modelling app like 3ds max or maya.
in that case the gfx card will do the job.

Thanks for the reply! Wow, I didn't know I could do that in puredata. I actually have some 3d knowledge, so the modelling part I can do, but can you perhaps explain how to go about this in pd?

[gemhead]
I
[pix_image]
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[pix_texture]
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[model]

A slit scan patch has already been developed with Gridflow. Download the library, follow the installation instructions and look for the slit-scan example. It may be difficult to understand what's going on in the patch, but I'm pretty sure that's what you're looking for. Hope it helps.

Download link:
http://gridflow.ca/

If someone would be still interested, here is the basic slit-scan using feedback and texture mapping.

http://www.pdpatchrepo.info/hurleur/slit_scan.pd