A 3D contour plot displays contour lines or filled contour bands on a three-dimensional surface, showing isolines of a function of two variables in 3D space. Unlike 2D contour plots that flatten the visualization, 3D contour plots preserve the surface geometry while highlighting level curves, making it easier to understand both the overall shape and specific value regions simultaneously. This visualization combines the spatial intuition of 3D surfaces with the precision of contour-based value identification.
""" anyplot.ai
contour-3d: 3D Contour Plot
Library: matplotlib 3.10.9 | Python 3.13.13
Quality: 95/100 | Updated: 2026-05-16
"""
import os
import matplotlib.pyplot as plt
import numpy as np
# Theme tokens
THEME = os.getenv("ANYPLOT_THEME", "light")
PAGE_BG = "#FAF8F1" if THEME == "light" else "#1A1A17"
INK = "#1A1A17" if THEME == "light" else "#F0EFE8"
INK_SOFT = "#4A4A44" if THEME == "light" else "#B8B7B0"
# Data - Terrain elevation data with realistic features
np.random.seed(42)
x = np.linspace(0, 10, 40)
y = np.linspace(0, 10, 40)
X, Y = np.meshgrid(x, y)
# Create realistic terrain with peaks and valleys (elevation in meters)
Z = 100 + 30 * np.sin(X / 2) * np.cos(Y / 2) + 20 * np.exp(-((X - 5) ** 2 + (Y - 5) ** 2) / 8)
# Create figure with 3D axes
fig = plt.figure(figsize=(16, 9), facecolor=PAGE_BG)
ax = fig.add_subplot(111, projection="3d", facecolor=PAGE_BG)
ax.xaxis.pane.set_facecolor(PAGE_BG)
ax.yaxis.pane.set_facecolor(PAGE_BG)
ax.zaxis.pane.set_facecolor(PAGE_BG)
# Plot surface with semi-transparency
surf = ax.plot_surface(X, Y, Z, cmap="viridis", alpha=0.6, edgecolor="none", antialiased=True)
# Add 3D contour lines on the surface
contours = ax.contour(X, Y, Z, levels=12, cmap="viridis", linewidths=2)
# Project contours onto the base plane (z = min)
z_offset = Z.min() - 5
ax.contour(X, Y, Z, levels=12, zdir="z", offset=z_offset, cmap="viridis", linewidths=1.5)
# Styling - theme-adaptive chrome
ax.set_xlabel("Distance East (km)", fontsize=20, color=INK, labelpad=15)
ax.set_ylabel("Distance North (km)", fontsize=20, color=INK, labelpad=15)
ax.set_zlabel("Elevation (m)", fontsize=20, color=INK, labelpad=15)
ax.set_title("contour-3d · matplotlib · anyplot.ai", fontsize=24, color=INK, pad=20)
# Tick params with theme-adaptive colors
ax.tick_params(axis="x", labelsize=16, colors=INK_SOFT)
ax.tick_params(axis="y", labelsize=16, colors=INK_SOFT)
ax.tick_params(axis="z", labelsize=16, colors=INK_SOFT)
# Set pane edge colors
ax.xaxis.pane.set_edgecolor(INK_SOFT)
ax.yaxis.pane.set_edgecolor(INK_SOFT)
ax.zaxis.pane.set_edgecolor(INK_SOFT)
ax.xaxis.pane.set_alpha(0.1)
ax.yaxis.pane.set_alpha(0.1)
ax.zaxis.pane.set_alpha(0.1)
# Set view angle
ax.view_init(elev=30, azim=45)
# Add colorbar with theme-adaptive colors
cbar = fig.colorbar(surf, ax=ax, shrink=0.6, aspect=15, pad=0.1)
cbar.set_label("Elevation (m)", fontsize=16, color=INK)
cbar.ax.tick_params(labelsize=14, colors=INK_SOFT)
plt.tight_layout()
plt.savefig(f"plot-{THEME}.png", dpi=300, bbox_inches="tight", facecolor=PAGE_BG)
Part of 3D Contour Plot on anyplot.ai.