Creating a Bezier Curve

Introduction

In this tutorial, we will learn how to create a Bezier Curve using Python's Matplotlib library. A Bezier Curve is a mathematical curve that is commonly used in computer graphics to create smooth and aesthetically pleasing shapes. We will create a simple example of a Bezier Curve using Matplotlib's PathPatch object.

VM Tips

After the VM startup is done, click the top left corner to switch to the Notebook tab to access Jupyter Notebook for practice.

Sometimes, you may need to wait a few seconds for Jupyter Notebook to finish loading. The validation of operations cannot be automated because of limitations in Jupyter Notebook.

If you face issues during learning, feel free to ask Labby. Provide feedback after the session, and we will promptly resolve the problem for you.

Skills Graph

Importing Libraries

To create a Bezier Curve using Matplotlib, we need to import the necessary libraries. We will import matplotlib.pyplot for creating the plot and matplotlib.patches for creating the PathPatch object.

import matplotlib.pyplot as plt
import matplotlib.patches as mpatches
import matplotlib.path as mpath

Creating the Path

Next, we will create the Path object for the Bezier Curve. The Path object takes in a list of vertices and codes that specify the type of path between the vertices. In this case, we will use a MOVETO code to move to the starting point, followed by two CURVE3 codes to specify the control points and ending point, and finally a CLOSEPOLY code to close the path.

Path = mpath.Path

bezier_path = Path([(0, 0), (1, 0), (1, 1), (0, 0)],
                   [Path.MOVETO, Path.CURVE3, Path.CURVE3, Path.CLOSEPOLY])

Creating the PathPatch Object

Now that we have the Path object, we can create the PathPatch object that will be used to draw the Bezier Curve on the plot. We will set the facecolor to 'none' so that only the curve is drawn and not filled.

bezier_patch = mpatches.PathPatch(bezier_path, fc="none")

Creating the Plot

We can now create the plot by adding the PathPatch object to the axes and plotting a red point that should lie on the curve. We will also set the title of the plot to 'Bezier Curve'.

fig, ax = plt.subplots()

ax.add_patch(bezier_patch)
ax.plot([0.75], [0.25], "ro")
ax.set_title('Bezier Curve')

plt.show()

The final code should look like this:

import matplotlib.pyplot as plt
import matplotlib.patches as mpatches
import matplotlib.path as mpath

Path = mpath.Path

bezier_path = Path([(0, 0), (1, 0), (1, 1), (0, 0)],
                   [Path.MOVETO, Path.CURVE3, Path.CURVE3, Path.CLOSEPOLY])

bezier_patch = mpatches.PathPatch(bezier_path, fc="none")

fig, ax = plt.subplots()

ax.add_patch(bezier_patch)
ax.plot([0.75], [0.25], "ro")
ax.set_title('Bezier Curve')

plt.show()

Summary

In this tutorial, we learned how to create a Bezier Curve using Python's Matplotlib library. We used the Path and PathPatch objects to create the curve and added it to a plot. We also plotted a red point on the curve to show that it lies on the curve. The Bezier Curve is commonly used in computer graphics to create smooth and aesthetically pleasing shapes.