In the Basic sub-tab of the modeling toolbox, right-click the Pen tool to reveal additional options, and click Bezier Curve.To activate the direct modeling Bezier tool:

The following animation illustrates the workflow. By default, both sides of the tangent move together. Dragging moves the tangents to shape the curve. When you click and drag in the viewport, an anchor and a pair of tangents are created. When you continue to click in the viewport, additional points are added to the curve. Depending on the Mode option, slightly different components draw in the interface.Įach time you click in the viewport with the Bezier Curve tool activated, you create an anchor which has no tangents and a sharp corner is created on your curve. The tangents determine the shape of the curve leading to an adjacent anchor. Anchors lie on the curve and determine the origin of the tangents. Bezier curves are a subset of Non-uniform Rational B-spline (NURBS) curves that are composed of two types of control vertices, anchors and tangents. The Bezier tool allows you to create a curve defined by control vertices.

Changing a Bezier Curve to Different Curve Type.

Notice, however, that the patch doesn't need to be bicubic each direction can be a different degree. The Mu and Mv matrices are constructed with the same formula as above. Here's a short list of the properties of Bernstein basis functions: Leveraging these properties will help us do more quick evaluations. Bernstein basis functions have some unique properties. Let's see if we can't use a trick or two to cut this down. Naive evaluation will take a long time computationally, especially considering that the binomial term is often expressed in terms of factorials.

Recall the formal Bernstein basis function form: The quickest way to do a single evaluation of a point on the Bezier surface is to evaluate the Bernstein basis functions directly. If you're not familiar with the Bezier formulation for curves, please read ' The Practical Guide to Bezier Curves' article first. I'm sure others here know more than I do, but I'd like to introduce some things here that can be helpful to those who want to delve into this topic. This isn't meant as a thorough exploration of the mathematics, but as a jump-off point. This is meant as a beginning guide to Bezier surfaces and some ways to implement them in practical code.