hi simon and welcome to the pd community..

it's a decent question and you will no doubt get a number of different responses..

depending on your system you have a few options: gem, pdp or gridflow, which all cover the imaging section of your question. gem however is probably the most appropriate as it covers both the 3D and the interactive part in one. gem allows you to interact with image, video and GL primitives in a 3D space.. it also covers input and depending on how you require live imagary to be captured you have varying levels of control, for example there is [pix_blob], which describes the average mass (gravity) of movement in terms of X+Y (which sounds like what you're after), there is [pix_hit] which allows you to describe parts of the image grid which trigger when the input passes through, or there is [pix_dump] which outputs the incoming pixel grid as a list which you can process with your own math.

as for your camera, it should be supported by gem, but DV support can be a bit sketchy on some platforms..

gem is part of the pd-extended build which runs on many systems..

this is a fairly broad answer to a broad question, i hope it helps..

dmotd

On Monday 16 March 2009 22:53:18 Simon Ball wrote:

Hi there

I'm having trouble realising an idea. I've got the software running (mac book pro) and managed to play with some of the examples, however I am new to PD, so bare with me!

I'm trying to generate a composition of images that float in 3D space. I want the images or layers to move and rotate towards areas of a screen where movement is detected. I don't need to track specific points of motion, simply to judge where movement is taking place. I think this will involve reading frames and analysing changes in pixels. Does that make sense?

I plan to use a mini DV camera to run this, on a high contrast background, although I've seen a similar method of recording movement with a webcam and processing, which worked pretty well. ( http://vimeo.com/1948430?pg=embed&sec= - tracks changes in pixels, although I'm not sure how).

I assume that this will involve some sort of trigonometry to move images towards points where motion is detected, although I'm not sure how to apply this in PD. Also, how to I generate a floating effect, much like 'easing' does in animation software. And can this work with 3D, mapped images in PD?

I hope thats clear, if a little broad, let me know you need any further info.

Thanks in advance for any suggestions/solutions.

Simon

Simon Ball

Video tracking is tricky, but the basics are not too hard. In the Pd- extended Help Browser, check out these patches:

manuals -> 2.Image -> 17.tracking.pd examples -> Gem -> 04.video -> 03.movement_detection.pd

I am guessing the first is the one you want, its based on background
subtractions, which is a widely used technique.

.hc

On Mar 16, 2009, at 12:53 PM, Simon Ball wrote:

Hi there

I'm having trouble realising an idea. I've got the software running
(mac book pro) and managed to play with some of the examples,
however I am new to PD, so bare with me!

I'm trying to generate a composition of images that float in 3D
space. I want the images or layers to move and rotate towards areas
of a screen where movement is detected. I don't need to track
specific points of motion, simply to judge where movement is taking
place. I think this will involve reading frames and analysing
changes in pixels. Does that make sense?

I plan to use a mini DV camera to run this, on a high contrast
background, although I've seen a similar method of recording
movement with a webcam and processing, which worked pretty well. (http://vimeo.com/1948430?pg=embed&sec=

• tracks changes in pixels, although I'm not sure how).

I assume that this will involve some sort of trigonometry to move
images towards points where motion is detected, although I'm not
sure how to apply this in PD. Also, how to I generate a floating
effect, much like 'easing' does in animation software. And can this
work with 3D, mapped images in PD?

I hope thats clear, if a little broad, let me know you need any
further info.

Thanks in advance for any suggestions/solutions.

Simon

Simon Ball _______________________________________________ Pd-list@iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list

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