Help with Skeleton Tracker for Live Projection on Moving Person
Hi everyone,
I'm currently working on a project where I want to project visual content with a beamer directly onto a person moving on stage. To achieve this, I'm experimenting with Millumin’s Skeleton Tracker.
Here is my current setup:
- I’m using a BirdDog camera, mounted relatively centered above the beamer.
- The camera feed comes into Millumin via NDI.
- I’ve applied the Skeleton Tracker effect to the camera input, and it tracks the person quite well.
- I’ve created 4 interaction mappings using the Interaction panel to move a graphical object (a yellow shape) in sync with the person's position.
However, I’m running into two main issues:
- The object doesn’t align exactly on top of the person’s body, but appears next to them. I assume this could be improved with calibration, but I couldn’t find where or how to do this.
- For the beamer to project accurately onto the person, the camera’s view must match the projector’s projection angle perfectly. But I’m struggling to align the two perspectives exactly — they are always slightly off. Is there a recommended way to calibrate the camera view to match the projector output?
I haven’t found much documentation or examples for the Skeleton Tracker, so any help or suggestions would be greatly appreciated.
Thanks in advance!
Comments
Hello @MotionSicknessMedia,
Do not use the calibration for this use case. In case you changed it, revert it back like that :
As you can see, the "output" values goes from -960 to 960 : this is because the size of my canvas is 1920x1080 (of course, the interaction for the Y goes from -540 to 540). You can use the option "stabilize" to make the move of your layer smoother.
However, do not expect perfect results with your method : you are missing a crucial data, the 3rd dimension. Tracking people on stage with accuracy requres dedicated hardware and complex algorithms. Check BlackTrax for example.
Best. Philippe