HandMod

Every modulation source on a computer is either a shape you drew in advance or a knob you have one spare hand for. HandMod is the third option, and unlike CamMod's deliberately dumb frame-differencing it knows what a hand is: twenty-one landmarks per hand, a face mesh, a body pose, updated every frame. That means a lane can follow the roll of your wrist rather than the movement of a blob, and roll is a thing you can repeat on purpose. A modulation source you cannot repeat is a modulation source you cannot perform with.

Forty-five quantities come out of the tracker, all normalised to 0-1 before a lane touches them: position, roll, pitch, yaw, spread, pinch and area for each hand; the separation between your hands and between your index fingers; mouth openness, brow height, smile and head angles; shoulder, elbow and torso geometry from the pose model. Eight lanes each pick one, scale it into a CC window, bend it through a curve and smooth it. Point two lanes at the same source with different curves and you have a crossfade you conduct.

The two-hand shape mode is the part worth trying first. Touch thumbs and index fingers on both hands and HandMod reads the quadrilateral you are framing, its area, its centre, its angle, as four more sources. Twist one hand and the quad crosses itself into two triangles, which the module reports as a discrete twist state you can map to something switch-like. It is a control surface you make out of the air and then deform, and there is no hardware that does this.

Privacy, plainly. The models are fetched once from a CDN and then everything runs in the page: frames go from the camera into a canvas, landmarks come out, and both are discarded before the next frame. Nothing is uploaded, not frames, not stills, not landmarks, not a summary, because there is no server in this loop at all. The browser's camera indicator is on while HandMod runs and goes off the moment you stop it. Turn off your Wi-Fi after the models load and the whole module works exactly the same; that is the test we would want to run, so run it.

Camera access is a request, not a requirement. Decline it and the module still renders, explains what it would have done and stays inspectable, the same posture the microphone modules take. A host without a camera API at all, which today means every native build, reports that honestly rather than showing a dead button; the capture path is behind an interface so a standalone shell can implement it over its own bridge later without any of the mapping code changing.