Saving a 3D-plot in a PDF 3D with Python

To save a 3D plot in a PDF with Python, you can use matplotlib's savefig() method. This approach creates standard 2D PDF files containing the 3D visualization, which is suitable for most documentation and sharing purposes.

Steps

• Set the figure size and adjust the padding between and around the subplots.

• Create a new figure or activate an existing figure.

• Add an 'ax' to the figure as part of a subplot arrangement with 3D projection.

• Create u, v, x, y and z data points using numpy.

• Plot a 3D wireframe or surface.

• Set the title and labels of the plot.

• Save the current figure using savefig() method with PDF format.

Example − Creating a 3D Wireframe Sphere

Here's how to create a 3D wireframe plot of a sphere and save it to PDF ?

import matplotlib.pyplot as plt
import numpy as np

# Set figure properties
plt.rcParams["figure.figsize"] = [7.00, 3.50]
plt.rcParams["figure.autolayout"] = True

# Create figure and 3D axis
fig = plt.figure()
ax = fig.add_subplot(111, projection='3d')

# Generate sphere data
u, v = np.mgrid[0:2 * np.pi:30j, 0:np.pi:20j]
x = np.cos(u) * np.sin(v)
y = np.sin(u) * np.sin(v)
z = np.cos(v)

# Plot 3D wireframe
ax.plot_wireframe(x, y, z, color="red")

# Set title and labels
ax.set_title("3D Wireframe Sphere")
ax.set_xlabel('X axis')
ax.set_ylabel('Y axis')
ax.set_zlabel('Z axis')

# Save as PDF
plt.savefig("sphere_3d.pdf", format='pdf', bbox_inches='tight')

# Display plot
plt.show()

The output will display the following 3D wireframe sphere ?

Customizing PDF Output

You can customize the PDF output with additional parameters ?

import matplotlib.pyplot as plt
import numpy as np

# Create a more complex 3D surface
fig = plt.figure(figsize=(10, 8))
ax = fig.add_subplot(111, projection='3d')

# Generate surface data
x = np.linspace(-5, 5, 50)
y = np.linspace(-5, 5, 50)
X, Y = np.meshgrid(x, y)
Z = np.sin(np.sqrt(X**2 + Y**2))

# Create surface plot
surf = ax.plot_surface(X, Y, Z, cmap='viridis', alpha=0.7)

# Add colorbar
fig.colorbar(surf)

# Set labels and title
ax.set_xlabel('X coordinate')
ax.set_ylabel('Y coordinate')
ax.set_zlabel('Z coordinate')
ax.set_title('3D Surface Plot')

# Save with high quality settings
plt.savefig("surface_3d.pdf", 
           format='pdf', 
           dpi=300, 
           bbox_inches='tight',
           facecolor='white')

plt.show()

Key Parameters for PDF Saving

Conclusion

Use matplotlib's savefig() method to save 3D plots as PDF files. The bbox_inches='tight' parameter ensures proper layout, while dpi=300 provides high-quality output suitable for printing and professional documentation.