De Casteljau Algorithm Python

Python Programming

The De Casteljau algorithm is a powerful technique used in computer graphics and computational geometry to evaluate Bézier curves. As a Python developer, I have found this algorithm to be incredibly useful in my work. In this article, I will delve deep into the De Casteljau algorithm in Python and provide my own personal insights and commentary along the way.

Understanding Bézier Curves

Before we dive into the De Casteljau algorithm, let’s first understand what Bézier curves are. A Bézier curve is a mathematical curve that is defined by a set of control points. These control points dictate the shape and behavior of the curve. Bézier curves are widely used in computer graphics, animation, and design applications.

The De Casteljau Algorithm

The De Casteljau algorithm is a recursive algorithm that allows us to evaluate a Bézier curve at any given point. It works by subdividing the curve into smaller segments until we reach a desired level of precision. Let’s see how this algorithm can be implemented in Python:

def de_casteljau(control_points, t):
if len(control_points) == 1:
return control_points[0]
new_points = []
for i in range(len(control_points) - 1):
new_point = (1 - t) * control_points[i] + t * control_points[i + 1]
return de_casteljau(new_points, t)

In the above code, the de_casteljau function takes in a list of control points and a parameter t which represents the position along the curve. If there is only one control point, it returns that point as the result. Otherwise, it subdivides the curve by calculating new points between each pair of adjacent control points based on the parameter t. This process is repeated recursively until we reach a single point, which is our final result.

By varying the value of t between 0 and 1, we can evaluate the Bézier curve at different positions along the curve. This gives us the ability to draw and animate smooth curves with precision.

Personal Insights

I have found the De Casteljau algorithm to be a elegant and efficient solution for evaluating Bézier curves. The recursive nature of the algorithm allows for easy implementation and intuitive understanding of how the curve is constructed. Furthermore, the ability to control the level of precision by adjusting the value of t gives us flexibility in generating smooth curves that meet our specific requirements.


The De Casteljau algorithm is a fundamental technique for evaluating Bézier curves in computer graphics. With its recursive approach and the ability to control precision, it offers a powerful tool for generating smooth curves. As a Python developer, I have enjoyed exploring and implementing this algorithm in my own projects. I hope this article has provided you with a deeper understanding of the De Casteljau algorithm in Python.