Plot image on plane in Matplotlib mplot3d

Question

I have a 3D scene created with Matplotlib and I would like to apply a chessboard like pattern on the bottom plane in the image below. Do you have any idea how to achieve this?

Here is the code to create this image:

import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D

# Create figure
plt.style.use('dark_background') # Dark theme
fig = plt.figure(frameon=False)
ax = fig.add_subplot(111, projection='3d')

# Make panes transparent
ax.xaxis.pane.fill = False # Left pane
ax.yaxis.pane.fill = False # Right pane
# ax.zaxis.pane.fill = False # Bottom pane

# Remove grid lines
ax.grid(False)

# Remove tick labels
ax.set_xticklabels([])
ax.set_yticklabels([])
ax.set_zticklabels([])

# Random data to illustrate
zdata = 15 * np.random.random(100)
xdata = np.sin(zdata) + 0.1 * np.random.randn(100)
ydata = np.cos(zdata) + 0.1 * np.random.randn(100)
ax.scatter3D(xdata, ydata, zdata, c=zdata, cmap='Greens')

# Print chart
file_path = 'charts/3d.png'
fig.savefig(file_path, bbox_inches='tight', pad_inches=0.05, transparent=True)

Andrea · Accepted Answer · 2020-01-22T14:36:50.577

You can generate a grid of rectangles and use pathpatch_2d_to_3d function from mpl_toolkits.mplot3d.art3d to insert then into the 3d scene:

import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D

from matplotlib.patches import Rectangle
import mpl_toolkits.mplot3d.art3d as art3d

# Create figure
plt.style.use('dark_background') # Dark theme
fig = plt.figure(frameon=False)
ax = fig.add_subplot(111, projection='3d')

# Make planes transparent
ax.xaxis.pane.fill = False # Left plane
ax.yaxis.pane.fill = False # Right plane
# ax.zaxis.pane.fill = False # Horizontal plane

# Remove grid lines
ax.grid(False)

# Remove tick labels
ax.set_xticklabels([])
ax.set_yticklabels([])
ax.set_zticklabels([])

# Draw chessboard on hortizontal plane
for x_index, x in enumerate(np.arange(-1, 1.1, 0.2)):
    for y_index, y in enumerate(np.arange(-1, 1.1, 0.2)):
        if (x_index+y_index)%2:
            p = Rectangle([x,y], 0.2, 0.2)
            ax.add_patch(p)
            art3d.pathpatch_2d_to_3d(p, z=0, zdir="z")

ax.set(xlim=(-1,1.1), ylim=(-1,1.2), zlim=(0,15))

# Random data to illustrate
zdata = 15 * np.random.random(100)
xdata = np.sin(zdata) + 0.1 * np.random.randn(100)
ydata = np.cos(zdata) + 0.1 * np.random.randn(100)
ax.scatter3D(xdata, ydata, zdata, c=zdata, cmap='Greens')

# Print chart
file_path = 'charts/3d.png'
fig.savefig(file_path, bbox_inches='tight', pad_inches=0.05, transparent=True)

EDIT: cleaner version

RECT_SIZE_X = 0.2
RECT_SIZE_Y = 0.2
xlims = (-1, 1)
ylims = (-1, 1)

for x_index, x_pos in enumerate(np.arange(xlims[0], xlims[1], RECT_SIZE_X)):
    for y_index, y_pos in enumerate(np.arange(ylims[0], ylims[1], RECT_SIZE_Y)):
        if (x_index+y_index)%2:
            p = Rectangle([x_pos, y_pos], RECT_SIZE_X, RECT_SIZE_Y, color='orange')
        else:
            p = Rectangle([x_pos, y_pos], RECT_SIZE_X, RECT_SIZE_Y, color='gray')
        ax.add_patch(p)
        art3d.pathpatch_2d_to_3d(p, z=0, zdir="z")

ax.set(xlim=xlims, ylim=ylims, zlim=(0,15))
# Transparent spines
ax.w_xaxis.line.set_color((1.0, 1.0, 1.0, 0.0))
ax.w_yaxis.line.set_color((1.0, 1.0, 1.0, 0.0))
ax.w_zaxis.line.set_color((1.0, 1.0, 1.0, 0.0))

# Transparent panes
ax.w_xaxis.set_pane_color((1.0, 1.0, 1.0, 0.0))
ax.w_yaxis.set_pane_color((1.0, 1.0, 1.0, 0.0))
ax.w_zaxis.set_pane_color((1.0, 1.0, 1.0, 0.0))

# No ticks
ax.set_xticks([]) 
ax.set_yticks([]) 
ax.set_zticks([])

it seems the last line triggers an error in your code snippet `ax.set(xlim=(-1,1.1), ylim=(-1,1.2), zlim=(0,15))` returns `SyntaxError: invalid syntax` — Alexis.Rolland, Jan 22 '20 at 12:29
I found the issue, adding one extra line after the for loop fixes it on my side — Alexis.Rolland, Jan 22 '20 at 12:41
since you seem gifted with matplotlib, would you have any idea how to do this one? https://stackoverflow.com/questions/59857203/remove-border-from-matplotlib-3d-pane/59857277 — Alexis.Rolland, Jan 22 '20 at 12:45
One more question if it's not too much asking... would you mind explaining the nested for loops? I understand they are used to compute the rectangles and their coordinates but I am not clear on the choice of the hard coded values you have used. — Alexis.Rolland, Jan 22 '20 at 14:07
I admit I did not think about it much, I just made a checkboard and then adjusted the x and y lims to make it work. I added a cleaner version of the code, it should be more self-explanatory, but ask if you have doubts. ps. If you leave there the plane, there is a small mismatch in the axis limits that I don't fully understand and handmade ad-hoc adjustments might be needed — Andrea, Jan 22 '20 at 14:39
[Here](https://stackoverflow.com/questions/16488182/removing-axes-margins-in-3d-plot) a possible workaround for the mismatch, but I would not use it. It seems like a matplotlib problem and they might want to patch this behavior in the future. — Andrea, Jan 22 '20 at 15:00
It’s precisely because of the small mismatch / offset in the previous version which I was asking to clarify. Your workaround looks good enough to me. Thanks!! — Alexis.Rolland, Jan 23 '20 at 00:15

Plot image on plane in Matplotlib mplot3d

1 Answers1