yade-dev team mailing list archive

[Václav Šmilauer <eudoxos@xxxxxxxx>]

> One remark on "separate scaling and (rotation+shear)".
> Actually, scaling IS shear, they are really exactly the same thing 
> represented in different coordinate systems. You can only separate 
> rotation. I'm sure you figured that already. ;)
Well, I still managed to separate them ;-) If you normalize transformed
axes, then transformation from physical (normalized) axes to the
transformed ones is just shear and rotation without scaling. It is Hsize
with columns normalized (as vectors), if you wish.


> The difference between pure shear and simple shear is there is a 
> rotation of the material (relative to the principal axis of the strain 
> rate tensor) in the second one. In this special case (simple shear), the 
> rotation needs nothing special and the current code works I think (or I 
> missed some details concerning bb's, collider, or interactions).
Everything should work now, including arbitrary transformations
(including rotations), as long as det(trsf)!=0 and the collider
requirements are not violated.