Exporting Plots as Image Files

The render() method allows users to directly plot the curves and surfaces using predefined visualization classes. This method takes some keyword arguments to control plot properties at runtime. Please see the class documentation on description of these keywords. The render() method also allows users to save the plots directly as a file and to control the plot window visibility. The keyword arguments that control these features are filename and plot, respectively.

The following example script illustrates creating a 3-dimensional Bézier curve and saving the plot as bezier-curve3d.pdf without popping up the Matplotlib plot window. filename argument is a string value defining the name of the file to be saved and plot flag controls the visibility of the plot window.

from geomdl import BSpline
from geomdl import utilities
from geomdl.visualization import VisMPL

# Create a 3D B-Spline curve instance (Bezier Curve)
curve = BSpline.Curve()

# Set up the Bezier curve
curve.degree = 3
curve.ctrlpts = [[10, 5, 10], [10, 20, -30], [40, 10, 25], [-10, 5, 0]]

# Auto-generate knot vector
curve.knotvector = utilities.generate_knot_vector(curve.degree, len(curve.ctrlpts))

# Set sample size
curve.sample_size = 40

# Evaluate curve
curve.evaluate()

# Plot the control point polygon and the evaluated curve
vis_comp = VisMPL.VisCurve3D()
curve.vis = vis_comp

# Don't pop up the plot window, instead save it as a PDF file
curve.render(filename="bezier-curve3d.pdf", plot=False)

This functionality strongly depends on the plotting library used. Please see the documentation of the plotting library that you are using for more details on its figure exporting capabilities.