The model from your code if only can perform tracing of paraxial rays？

[lindeMAX]

If i got it right, it should work like this:

ray_group = tp.ray_plane(geo, [0, 1, 0], 0.1, d=[0,m.sqrt(0.5),m.sqrt(0.5)], nrays=100)

But it doesn't and for some reason and also for some reason the length of the direction vector has to match exactly 1