Bézier curve
The interpretation given above is valid for a nonrational Bézier curve. To evaluate a rational Bézier curve in formula_39, we may project the point into formula_40; for example, a curve in three dimensions may have its control points formula_41 and weights formula_42 projected to the weighted control points formula_43. The algorithm then proceeds as usual, interpolating in formula_44. The resulting four-dimensional points may be projected back into three-space with a perspective divide.