What is the algorithm to convert a quadratic bezier (with 3 points) to a

Question

Editorial Team

Asked: May 15, 20262026-05-15T14:11:34+00:00 2026-05-15T14:11:34+00:00

What is the algorithm to convert a quadratic bezier (with 3 points) to a cubic one (with 4 points)?

You must login to add an answer.

Need An Account,

Editorial Team · Answer 1 · 2026-05-15T14:11:34+00:00

Any quadratic spline can be expressed as a cubic (where the cubic term is zero). The end points of the cubic will be the same as the quadratic’s.

CP₀ = QP₀
CP₃ = QP₂

The two control points for the cubic are:

CP₁ = QP₀ + 2/3 *(QP₁-QP₀)
CP₂ = QP₂ + 2/3 *(QP₁-QP₂)

…There is a slight error introduced due to rounding, but it is unlikely to be noticeable.

The Archive Base Latest Questions