3D Isosurface Plots in Python
How to make 3D Isosurface Plots in Python with Plotly.
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With go.Isosurface
, you can plot isosurface contours of a scalar field value
, which is defined on x
, y
and z
coordinates.
Basic Isosurface¶
In this first example, we plot the isocontours of values isomin=2
and isomax=6
. In addition, portions of the sides of the coordinate domains for which the value is between isomin
and isomax
(named the caps
) are colored. Please rotate the figure to visualize both the internal surfaces and the caps surfaces on the sides.
import plotly.graph_objects as go
fig= go.Figure(data=go.Isosurface(
x=[0,0,0,0,1,1,1,1],
y=[1,0,1,0,1,0,1,0],
z=[1,1,0,0,1,1,0,0],
value=[1,2,3,4,5,6,7,8],
isomin=2,
isomax=6,
))
fig.show()
Removing caps when visualizing isosurfaces¶
For a clearer visualization of internal surfaces, it is possible to remove the caps (color-coded surfaces on the sides of the visualization domain). Caps are visible by default.
import plotly.graph_objects as go
import numpy as np
X, Y, Z = np.mgrid[-5:5:40j, -5:5:40j, -5:5:40j]
# ellipsoid
values = X * X * 0.5 + Y * Y + Z * Z * 2
fig = go.Figure(data=go.Isosurface(
x=X.flatten(),
y=Y.flatten(),
z=Z.flatten(),
value=values.flatten(),
isomin=10,
isomax=40,
caps=dict(x_show=False, y_show=False)
))
fig.show()
Modifying the number of isosurfaces¶
import plotly.graph_objects as go
import numpy as np
X, Y, Z = np.mgrid[-5:5:40j, -5:5:40j, -5:5:40j]
# ellipsoid
values = X * X * 0.5 + Y * Y + Z * Z * 2
fig = go.Figure(data=go.Isosurface(
x=X.flatten(),
y=Y.flatten(),
z=Z.flatten(),
value=values.flatten(),
isomin=10,
isomax=50,
surface_count=5, # number of isosurfaces, 2 by default: only min and max
colorbar_nticks=5, # colorbar ticks correspond to isosurface values
caps=dict(x_show=False, y_show=False)
))
fig.show()
Changing the opacity of isosurfaces¶
import plotly.graph_objects as go
import numpy as np
X, Y, Z = np.mgrid[-5:5:40j, -5:5:40j, -5:5:40j]
# ellipsoid
values = X * X * 0.5 + Y * Y + Z * Z * 2
fig = go.Figure(data=go.Isosurface(
x=X.flatten(),
y=Y.flatten(),
z=Z.flatten(),
value=values.flatten(),
opacity=0.6,
isomin=10,
isomax=50,
surface_count=3,
caps=dict(x_show=False, y_show=False)
))
fig.show()
Isosurface with Additional Slices¶
Here we visualize slices parallel to the axes on top of isosurfaces. For a clearer visualization, the fill
ratio of isosurfaces is decreased below 1 (completely filled).
import plotly.graph_objects as go
import numpy as np
X, Y, Z = np.mgrid[-5:5:40j, -5:5:40j, -5:5:40j]
# ellipsoid
values = X * X * 0.5 + Y * Y + Z * Z * 2
fig = go.Figure(data=go.Isosurface(
x=X.flatten(),
y=Y.flatten(),
z=Z.flatten(),
value=values.flatten(),
isomin=5,
isomax=50,
surface_fill=0.4,
caps=dict(x_show=False, y_show=False),
slices_z=dict(show=True, locations=[-1, -3,]),
slices_y=dict(show=True, locations=[0]),
))
fig.show()
Multiple Isosurfaces with Caps¶
import plotly.graph_objects as go
import numpy as np
X, Y, Z = np.mgrid[-5:5:40j, -5:5:40j, 0:5:20j]
values = X * X * 0.5 + Y * Y + Z * Z * 2
fig = go.Figure(data=go.Isosurface(
x=X.flatten(),
y=Y.flatten(),
z=Z.flatten(),
value=values.flatten(),
isomin=30,
isomax=50,
surface=dict(count=3, fill=0.7, pattern='odd'),
caps=dict(x_show=True, y_show=True),
))
fig.show()
Changing the default colorscale of isosurfaces¶
import plotly.graph_objects as go
import numpy as np
X, Y, Z = np.mgrid[-5:5:40j, -5:5:40j, -5:5:40j]
# ellipsoid
values = X * X * 0.5 + Y * Y + Z * Z * 2
fig = go.Figure(data=go.Isosurface(
x=X.flatten(),
y=Y.flatten(),
z=Z.flatten(),
value=values.flatten(),
colorscale='BlueRed',
isomin=10,
isomax=50,
surface_count=3,
caps=dict(x_show=False, y_show=False)
))
fig.show()
Customizing the layout and appearance of isosurface plots¶
import plotly.graph_objects as go
import numpy as np
X, Y, Z = np.mgrid[-5:5:40j, -5:5:40j, 0:5:20j]
values = X * X * 0.5 + Y * Y + Z * Z * 2
fig = go.Figure(data=go.Isosurface(
x=X.flatten(),
y=Y.flatten(),
z=Z.flatten(),
value=values.flatten(),
isomin=30,
isomax=50,
surface=dict(count=3, fill=0.7, pattern='odd'),
showscale=False, # remove colorbar
caps=dict(x_show=True, y_show=True),
))
fig.update_layout(
margin=dict(t=0, l=0, b=0), # tight layout
scene_camera_eye=dict(x=1.86, y=0.61, z=0.98))
fig.show()
Reference¶
See https://plotly.com/python/reference/isosurface/ for more information and chart attribute options!
What About Dash?¶
Dash is an open-source framework for building analytical applications, with no Javascript required, and it is tightly integrated with the Plotly graphing library.
Learn about how to install Dash at https://dash.plot.ly/installation.
Everywhere in this page that you see fig.show()
, you can display the same figure in a Dash application by passing it to the figure
argument of the Graph
component from the built-in dash_core_components
package like this:
import plotly.graph_objects as go # or plotly.express as px
fig = go.Figure() # or any Plotly Express function e.g. px.bar(...)
# fig.add_trace( ... )
# fig.update_layout( ... )
from dash import Dash, dcc, html
app = Dash()
app.layout = html.Div([
dcc.Graph(figure=fig)
])
app.run(debug=True, use_reloader=False) # Turn off reloader if inside Jupyter
