leg
thigh only → hip angle
thigh + shank → knee angle
movement
speed
×
pause
reset
measurement noise
σ
mm
Gaussian, per marker, per frame
skin: wobbling mass
f
along
Hz
f
across
Hz
ζ
skin: slide with joint angle
gain
×
1× ≈ 0.15–0.45 mm per degree
of joint flexion, marker by marker
unconstrained IK: frame from
m
1
, m
2
only (lecture)
least-squares fit, all three
show
true leg
unconstrained IK
constrained IK
hip pinned · dots are the
measured
markers
knee angle
RMS error, last 8 s: unconstrained
–
° constrained
–
°
knee gap
in the unconstrained reconstruction:
–
mm
hip RMS:
–
° /
–
° unconstrained hip off its pin by
–
mm