On a theatre stage, track a moving rectangular screen/panel, capturing its position, scale, and rotation for use in TouchDesigner and send via OSC to Millumin.

Beginners
1

Hello, I’m a beginner in TouchDesigner, and I’m looking for a way to send to Millumin a system that can track, in a theatre setting, a white rolling panel—probably rectangular—moving from point A to point B, manipulated by actors. For communication, I’m thinking of using OSC signals.

So far I have: camera → “ndiin” → “level1” → “tresh” → “blobtrack”, but I’m stuck on the next steps.

If I use a “TOP to CHOP,” I only get the RGBA signals, but what I really need are XY coordinates, scale, rotation, etc., and I’m a bit lost there!

I’ve been trying, but I’m stuck. In Blob Track, when I click on the pink arrow, it seems like I can get usable coordinates, but I haven’t been able to make them work.

Does anyone have any suggestions or ideas, please?

Thank you so much!

Mathieu

2

Bonjour Mathieu,

It is easier if you post also a file or a photo of your try.

Here is a quick exemple of what could help you to use blobtrack:

  • I move a square on the screen with some noise and I move another rectangle accordingly to the blob coord (minus 0.5)
  • in real world, you must first filter the image (treshold, chromakey, level) to have the best contrast between object and background
  • You obtain the blob coordinate ading an info chop to the blobtrack top

In stage condition, it is not so easy :-), Changing lights, shadows, paralax…

But you have the first steps.

Hoping to heard you somewhere in Paris.

Have a nice day,

Jacques

PS Et si vous avez besoin d’un artiste visuel pour vous aider, n’hésitez pas !

blobTrack.toe (4.7 KB)