I can't animate a surface with Mayavi

Here I've shown the code to plot a cube and animate it so that it grows out from a height of 0.01 to a height of 1 using mlab.mesh. What yield does is that it returns control to the decorator so that the scene can be updated.

import numpy as np
from mayavi import mlab

s = 0.01
X = np.array([[0,0,1,1],[0,0,1,1],[0,0,0,0],[1,1,1,1]])
Y = np.array([[0,1,1,0],[0,1,1,0],[1,0,0,1],[1,0,0,1]])
Z = np.array([[0,0,0,0],[s,s,s,s],[0,0,s,s],[0,0,s,s]])

m = mlab.mesh(X, Y, Z)

@mlab.animate(delay=20)
def anim():
    for i in range(1,101):
        print(i, end='\r')
        m.mlab_source.z = np.array([[0,0,0,0],[s*i,s*i,s*i,s*i],[0,0,s*i,s*i],[0,0,s*i,s*i]])
        yield

anim()
mlab.show()

scalars is one way to access the underlying data structure if that data structure has the scalars attribute. However, for mesh that attribute is not used, rather you want to access z and set those values. I would not know what your specific issue with u if unless there is a traceback to work from. The same with yield - I see no reason why that keyword would stop the animation at any particular step.

The code below shows, instead of a box evolving over time, a surface evolving with time.

import numpy as np
from mayavi import mlab

def evolving_function(X, Y, t, Lx=1, Ly=1):
    
    return np.sin(X+Lx*t)*np.sin(Y+Ly*t)

Lx, Ly = 1,2

x = np.linspace(-10,10,100)
y = np.linspace(-10,10,100)
X,Y = np.meshgrid(x,y)
X, Y = X.T, Y.T
s = evolving_function(X, Y, 0, Lx=Lx, Ly=Ly)

m = mlab.surf(X, Y, s)

dt = 50
t = 10
steps = int(10*1000/dt)

@mlab.animate(delay=dt)
def anim():
     for i in range(1,steps):
         m.mlab_source.scalars = evolving_function(X, Y, dt*i, Lx=Lx, Ly=Ly)
         yield

anim()
mlab.show()