jointValue method
A hinge's angle (radians) or a slider's position (metres) — body A's, measured from body B (or the world) — the same quantity a position motor drives; 0 for other joints.
Implementation
@override
double jointValue(int joint) {
final j = joints[joint];
final measured =
j != null &&
(j.settings.kind == JointKind3D.hinge ||
j.settings.kind == JointKind3D.slider);
return measured && j.motorState == MotorState3D.position
? j.motorTarget
: 0;
}