I am not able to wrap my head around setting up a shear transformation…
The xform wants a base plane and 3 “scale” vectors… Base plane, OK, but how do the scale vectors work?
Let’s say I want to take a simple cube with the lower left corner at the World origin, and shear it over 45° along the +Y axis (looking at it in right view, that would be a shear angle of -45° if one used the shear command)… I’ve tried a few things, but I cannot figure out how to set this up yet… I can manage to scale along one or more axes, but not shear over… Do I have to somehow align the base plane to the shear axis?
I understand something like that
Vec 1 = 1: 1 (Scale factor)
FirstArray X = Direction and size for X
SecondArray Y = direction and size for Y, x element in this array determines Your wanted angle.
Third Z = direction and size for Z
I see that rhinoscriptsyntax.XformShear() docs talk about ‘scale factors’,
then I think that the coordinates of the object (relative to the reference plane) gets multiplied by the vectors and then summed to obtain the target points … maybe …