The Graph2d makes use of
Catmull-Rom spline interpolation.
The user can configure these per group, or globally. In this example we show all 4 possiblities. The differences are in the parametrization of
the curves. The options are
uniform
,
chordal
and
centripetal
. Alternatively you can disable the Catmull-Rom interpolation and
a linear interpolation will be used. The
centripetal
parametrization produces the best result (no self intersection, yet follows the line closely) and is therefore the default setting.
For both the
centripetal
and
chordal
parametrization, the distances between the points have to be calculated and this makes these methods computationally intensive
if there are very many points. The
uniform
parametrization still has to do transformations, though it does not have to calculate the distance between point. Finally, the
linear interpolation is the fastest method. For more on the Catmull-Rom method,
C. Yuksel et al. have an interesting paper titled ″On the parametrization of Catmull-Rom Curves″.