title: How to plot a 3D scatter graph with a specified color for everypoint
body: <p>This question might be stupid but I can't find the answer. I'm using python and I want to plot a scatter graph where x is of size Nx, y of size Ny, z of size Nz and where for  every point (x[i] , y[j], z[k]) I have an intensity I[i,j,k] which is a real number.</p>
  
  <p>I would like to plot this scatter graph where every point of coordinates (x,y,z) has a color depending on the intensity </p>