Shape of AlphaGridMask is transposed

[NagabhushanSN95]

trafficstars

When creating the AlphaGridMask here, the alpha grid that is passed is of shape (size_z, size_y, size_x) instead of (size_x, size_y, size_z) because of the transpose operation here. However, when the alphaMask is sampled to determine whether or not to query a sigma and color of a 3D point here, the coordinates passed are (x,y,z) and not (z,y,x). Wouldn't this cause an error? It will check the alpha of a different point.