This is the whiteboard. Ink lands here, decoupled from the camera view.
Pinch thumb + index and drag to draw. Pinch and hold still
for ~350ms to open the tool/size picker, then drag through it and release
to confirm.
Camera (drag me)-
Controls
Fallback toolbar (accessibility)
Size
Physical Pen Mode (experimental)
Honest limits: this is a lightweight HSV color-blob bias,
not real pencil-tip detection. It samples one color from a target box, then
looks for that color near your hand each frame. It will misfire on
similar-colored backgrounds/skin tones and silently falls back to the bare
fingertip whenever it can't find a confident match. See README for what a
real "Physical Pen Mode" would need.