Between (x1,y1,z1)(x_1, y_1, z_1)(x1,y1,z1) and (x2,y2,z2)(x_2, y_2, z_2)(x2,y2,z2): (x2−x1)2+(y2−y1)2+(z2−z1)2\sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2 + (z_2 - z_1)^2}(x2−x1)2+(y2−y1)2+(z2−z1)2.