how to set camera position for 3d plots using python matplotlib

Question

I m learning how to use mplot3d to produce nice plots of 3d data and I m pretty happy so far  What I am trying to do at the moment is a little animation of a rotating surface  For that purpose  I need to set a camera position for the 3D projection  I guess this must be possible since a surface can be rotated using the mouse when using matplotlib interactively  But how can I do this from a script  I found a lot of transforms in mpl toolkits mplot3d proj3d but I could not find out how to use these for my purpose and I didn t find any example for what I m trying to do

User · Answer

What would be handy would be to apply the Camera position to a new plot. So I plot, then move the plot around with the mouse changing the distance. Then try to replicate the view including the distance on another plot. I find that axx.ax.get_axes() gets me an object with the old .azim and .elev.

IN PYTHON...

axx=ax1.get_axes()
azm=axx.azim
ele=axx.elev
dst=axx.dist       # ALWAYS GIVES 10
#dst=ax1.axes.dist # ALWAYS GIVES 10
#dst=ax1.dist      # ALWAYS GIVES 10

Later 3d graph...

ax2.view_init(elev=ele, azim=azm) #Works!
ax2.dist=dst                       # works but always 10 from axx

EDIT 1... OK, Camera position is the wrong way of thinking concerning the .dist value. It rides on top of everything as a kind of hackey scalar multiplier for the whole graph.

This works for the magnification/zoom of the view:

xlm=ax1.get_xlim3d() #These are two tupples
ylm=ax1.get_ylim3d() #we use them in the next
zlm=ax1.get_zlim3d() #graph to reproduce the magnification from mousing
axx=ax1.get_axes()
azm=axx.azim
ele=axx.elev

Later Graph...

ax2.view_init(elev=ele, azim=azm) #Reproduce view
ax2.set_xlim3d(xlm[0],xlm[1])     #Reproduce magnification
ax2.set_ylim3d(ylm[0],ylm[1])     #...
ax2.set_zlim3d(zlm[0],zlm[1])     #...

User · Answer

Try the following code to find the optimal camera position Move the viewing angle of the plot using the keyboard keys as mentioned in the if clause  Use print to get the camera positions  def move view event       ax autoscale enable False  axis  both        koef   8     zkoef    ax get zbound   0  - ax get zbound   1     koef     xkoef    ax get xbound   0  - ax get xbound   1     koef     ykoef    ax get ybound   0  - ax get ybound   1     koef        Map an motion to keyboard shortcuts     if event key     quot ctrl down quot           ax set ybound ax get ybound   0    xkoef  ax get ybound   1    xkoef      if event key     quot ctrl up quot           ax set ybound ax get ybound   0  - xkoef  ax get ybound   1  - xkoef      if event key     quot ctrl right quot           ax set xbound ax get xbound   0    ykoef  ax get xbound   1    ykoef      if event key     quot ctrl left quot           ax set xbound ax get xbound   0  - ykoef  ax get xbound   1  - ykoef      if event key     quot down quot           ax set zbound ax get zbound   0  - zkoef  ax get zbound   1  - zkoef      if event key     quot up quot           ax set zbound ax get zbound   0    zkoef  ax get zbound   1    zkoef        zoom option     if event key     quot alt up quot           ax set xbound ax get xbound   0  0 90  ax get xbound   1  0 90          ax set ybound ax get ybound   0  0 90  ax get ybound   1  0 90          ax set zbound ax get zbound   0  0 90  ax get zbound   1  0 90      if event key     quot alt down quot           ax set xbound ax get xbound   0  1 10  ax get xbound   1  1 10          ax set ybound ax get ybound   0  1 10  ax get ybound   1  1 10          ax set zbound ax get zbound   0  1 10  ax get zbound   1  1 10             Rotational movement     elev ax elev     azim ax azim     if event key     quot shift up quot           elev  10     if event key     quot shift down quot           elev- 10     if event key     quot shift right quot           azim  10     if event key     quot shift left quot           azim- 10      ax view init elev  elev  azim   azim         print which ever variable you want       ax figure canvas draw    fig canvas mpl connect  quot key press event quot   move view   plt show

User · Answer

Minimal example varying azim  dist and elev To add some simple sample images to what was explained at  https   stackoverflow com a 12905458 895245 Here is my test program     usr bin env python3  import sys  import matplotlib pyplot as plt from matplotlib import cm from matplotlib ticker import LinearLocator  FormatStrFormatter import numpy as np  fig   plt figure   ax   fig gca projection  3d    if len sys argv   gt  1      azim   int sys argv 1   else      azim   None if len sys argv   gt  2      dist   int sys argv 2   else      dist   None if len sys argv   gt  3      elev   int sys argv 3   else      elev   None    Make data  X   np arange -5  6  1  Y   np arange -5  6  1  X  Y   np meshgrid X  Y  Z   X  2    Plot the surface  surf   ax plot surface X  Y  Z  linewidth 0  antialiased False     Labels  ax set xlabel  x   ax set ylabel  y   ax set zlabel  z    if azim is not None      ax azim   azim if dist is not None      ax dist   dist if elev is not None      ax elev   elev  print  ax azim       format ax azim   print  ax dist       format ax dist   print  ax elev       format ax elev    plt savefig       main          png  format ax azim  ax dist  ax elev       format  png       bbox inches  tight      Running it without arguments gives the default values  ax azim   -60 ax dist   10 ax elev   30  main -60 10 30 png  Vary azim The azimuth is the rotation around the z axis e g    0 means  quot looking from  x quot  90 means  quot looking from  y quot   main -60 10 30 png  main 0 10 30 png  main 60 10 30 png  Vary dist dist seems to be the distance from the center visible point in data coordinates  main -60 10 30 png  main -60 5 30 png  main -60 20 -30 png  Vary elev From this we understand that elev is the angle between the eye and the xy plane  main -60 10 60 png  main -60 10 30 png  main -60 10 0 png  main -60 10 -30 png  Tested on matpotlib  3 2 2

User · Answer

By  camera position   it sounds like you want to adjust the elevation and the azimuth angle that you use to view the 3D plot  You can set this with ax view init  I ve used the below script to first create the plot  then I determined a good elevation  or elev  from which to view my plot   I then adjusted the azimuth angle  or azim  to vary the full 360deg around my plot  saving the figure at each instance  and noting which azimuth angle as I saved the plot    For a more complicated camera pan  you can adjust both the elevation and angle to achieve the desired effect       from mpl toolkits mplot3d import Axes3D     ax   Axes3D fig      ax scatter xx yy zz  marker  o   s 20  c  goldenrod   alpha 0 6      for ii in xrange 0 360 1           ax view init elev 10   azim ii          savefig  movie d png    ii

[python] how to set "camera position" for 3d plots using python/matplotlib?

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