matplotlib “rotate” gradient

Question

I have this code that display a triangle filled with a gradient.

from mpl_toolkits.mplot3d import axes3d
import matplotlib.pyplot as plt
import numpy as np

fig = plt.figure()
ax = fig.gca(projection='3d')

X, Y = np.meshgrid(np.linspace(0,1), np.linspace(0,1)) 
Z = 1.-X-Y
Z[Z<0] = 0

cset = ax.contourf(X, Y, Z, zdir='x', levels=np.linspace(0,1),offset=0, cmap=plt.cm.jet)
ax.set_xlabel('X')
ax.set_xlim(0, 1)
ax.set_ylabel('Y')
ax.set_ylim(0,1)
ax.set_zlabel('Z')
ax.set_zlim(0,1)    
plt.show()

How can I have the gradient "slices" in the other "direction"? I mean, the gradient should look like this:

Answer 1

The answer to this question has already been given here:

Fill a triangle in 3D matplolib plot with a color gradient

where I show two ways of producing a gradient fill in a 3D triangle using contourf and plot_surface .