Nephroid of Freeth
with its Inversion
The curves are defined by these equations:
r(t) = (1 - morph*sin(t/2))
c(t) = [r(t) * cos(t), r(t) * sin(t)]
This curve family has been studied because
of its double and triple points and its
double tangency point.
Its inversion has the same behaviour.
Inversion(vector) = (radius / |vector|)^2 * vector