Numpy mgrid/ arange

Question

I have a bunch of arrays around 10,000~ 10000000. each containing coordinates points x,y,z. I have successfully stored those in Numpy array. i have generated maxi and mini using

np.array(np.amin(Vertex_combined[:,:,:],axis=1))

np.array(np.amax(Vertex_combined[:,:,:],axis=1))

these generate 2 ranges

maxs=array([[406.78, 805.73, 345.14],
           [407.57, 805.83, 345.14],
           [407.9 , 805.83, 314.19]])

mins=array([[405.05, 805.52, 314.15],
           [405.84, 805.62, 314.15],
           [406.78, 805.19, 309.75]])

Now I need to generate

np.mgrid[mins[1,0]:maxs[1,0]:0.5, mins[1,1]:maxs[1,1]:0.5].reshape(2,-1).T

array([[405.84, 805.62],
       [406.34, 805.62],
       [406.84, 805.62],
       [407.34, 805.62]])

this works for single array by when i try

np.mgrid[mins[:,0]:maxs[:,0]:0.5, mins[:,1]:maxs[:,1]:0.5].reshape(2,-1).T

doesn't work. Any help or explanation for what I'm doing wrong would be of great help. thank you,

Traceback (most recent call last):
  File "C:\Users\R414065\AppData\Local\Programs\Python\Python38\lib\site-packages\numpy\lib\index_tricks.py", line 164, in __getitem__
    int(math.ceil((kk.stop - start) / (step * 1.0))))
TypeError: only size-1 arrays can be converted to Python scalars

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<pyshell#12>", line 1, in <module>
    np.hstack(np.mgrid[mins[:,0]:maxs[:,0]:0.5, mins[:,2]:maxs[:,2]:0.5].reshape(2,-1).T)
  File "C:\Users\R414065\AppData\Local\Programs\Python\Python38\lib\site-packages\numpy\lib\index_tricks.py", line 194, in __getitem__
    step = key.step
AttributeError: 'tuple' object has no attribute 'step'