plotting of 3-d softmax function using matplotlib - python-3.x

Question

I would like to illustrate a detailed function similar to the softmax function.
The formula is as shown in the image.
I wrote it in python based on the following blog. Sorry, written in Japanese.
https://www.anarchive-beta.com/entry/2020/06/07/180000
import numpy as np
import matplotlib.pyplot as plt
%matplotlib inline
import matplotlib
from mpl_toolkits.mplot3d.axes3d import Axes3D
%matplotlib notebook
def softmax(x, a, b, d):
x = x - np.max(x, axis=-1, keepdims=True)
return (np.exp(a * (x - d))*b / np.sum(np.exp(a * (x - d)), axis=-1, keepdims=True))
# input
x_vals = np.arange(0, 10, 0.01)
x2_vals = np.arange(0, 10, 0.01)
X0_vals, X1_vals = np.meshgrid(x_vals, x2_vals)
X_vals = np.array([
X0_vals.flatten(),
X1_vals.flatten()
]).T
print(X_vals)
print(X_vals[:5])
print(X_vals.shape)
input_shape = X0_vals.shape
print(input_shape)
Y_vals = softmax(X_vals, 12, 0.8, [10,10])
print(np.round(Y_vals[:5], 3))
print(np.sum(Y_vals[:5], axis=1))
Y0_vals = np.array(Y_vals[:, 0]).reshape(input_shape)
fig = plt.figure(figsize=(5, 5))
ax = Axes3D(fig)
ax.plot_wireframe(X0_vals, X1_vals, Y0_vals, label='$y_0$')
ax.set_xlabel('$x_0$')
ax.set_ylabel('$x_1$')
ax.set_zlabel('$y_0$')
ax.set_title('Softmax Function', fontsize=20)
ax.legend()
ax.set_zlim(0, 1)
ax.view_init(elev=20, azim=240)
plt.show()
Y_vals = softmax(X_vals, 12, 0.8, 0)
print(np.round(Y_vals[:5], 3))
print(np.sum(Y_vals[:5], axis=1))
Y0_vals = np.array(Y_vals[:, 0]).reshape(input_shape)
fig = plt.figure(figsize=(5, 5))
ax = Axes3D(fig)
ax.plot_wireframe(X0_vals, X1_vals, Y0_vals, label='$y_0$')
ax.set_xlabel('$x_0$')
ax.set_ylabel('$x_1$')
ax.set_zlabel('$y_0$')
ax.set_title('Softmax Function', fontsize=20)
ax.legend()
ax.set_zlim(0, 1)
ax.view_init(elev=20, azim=240)
plt.show()
(1)
I try to plot the picture with a_1 = a_2 = 12, b = 0.8, c_1 = c_2 = 12. However, I could not find the differences with a_1 = a_2 = 12, b = 0.8, c_1 = c_2 = 0.
How should I write the code?
(2)
I have no idea to plot when a_1 is not equal to a_2, or c_1 is not equal to c_2.
(3)
I would like to overlap a scatterplot of any point on a function, but it does not overlap properly.
There might be similar questions, but I'm not so familiar with the 3-D plot, so I would be glad to show me the details.