Added example of using the custom hillshading on a 3D surface plot

joferkington · joferkington · commit 31a423967424 · 2014-07-25T20:12:49.000-05:00
diff --git a/examples/mplot3d/custom_shaded_3d_surface.py b/examples/mplot3d/custom_shaded_3d_surface.py
@@ -0,0 +1,31 @@
+"""
+Demonstrates using custom hillshading in a 3D surface plot.
+"""
+from mpl_toolkits.mplot3d import Axes3D
+from matplotlib import cbook
+from matplotlib import cm
+from matplotlib.colors import LightSource
+import matplotlib.pyplot as plt
+import numpy as np
+
+dem = np.load(cbook.get_sample_data('jacksboro_fault_dem.npz'))
+z = dem['elevation']
+nrows, ncols = z.shape
+x = np.linspace(dem['xmin'], dem['xmax'], ncols)
+y = np.linspace(dem['ymin'], dem['ymax'], nrows)
+x, y = np.meshgrid(x, y)
+
+region = np.s_[5:50, 5:50]
+x, y, z = x[region], y[region], z[region]
+
+fig, ax = plt.subplots(subplot_kw=dict(projection='3d'))
+
+ls = LightSource(270, 45)
+# To use a custom hillshading mode, override the built-in shading and pass
+# in the rgb colors of the shaded surface calculated from "shade".
+rgb = ls.shade(z, cmap=cm.gist_earth, vert_exag=0.1, blend_mode='soft')
+surf = ax.plot_surface(x, y, z, rstride=1, cstride=1, facecolors=rgb,
+                       linewidth=0, antialiased=False, shade=False)
+
+plt.show()
+
