We are working on a very space constrained custom spatial accessory. Since the form factor of the device is small, we need to add small LEDs producing small blob diameters with accordingly small distance between them. To better estimate the amount, size, and distance of the LEDs it would help to know which image sensors and field of view the six world‑facing tracking cameras have.
Camera specs of world-facing tracking cameras.
Hi @NMO13
I can't share the camera specs, but you shouldn't need them since the constraints are fixed by the spec, not the device. The Spatial Accessories section of the Accessory Design Guidelines sets blob size and spacing independently of how big the accessory is.
Count: Four or more LEDs must be visible from every viewing angle, forming a different pattern at each, with no more than 30 recommended.
Size: Each LED must appear as a spot 5-12 mm across at 0.7 m. That's what the camera sees, not the size of the emitter, so a 1 x 0.5 mm part can still produce a 10 mm spot once light spreads through the housing.
Spacing: At least twice the spot size, so roughly 10 mm center-to-center minimum. This is a hard floor, and smaller LEDs won't lower it.
Section 20.6.1 lists the rest. One worth flagging for a compact or flat body: at every viewing angle, at least one LED must sit on a different plane from the others.
Tips: Running xcrun createml accessorytracker validates your annotated USDZ before training and warns about LED patterns that look too similar from different angles, so review those warnings. ARKit Accessory Tracking Debug View (Design Guidelines §20.9.4) then shows the actual spots through the tracking cameras, so you can confirm they don't merge. Refer to Preparing spatial accessories for tracking and Working with generic spatial accessories for more details.