`SF::get_transformed_pts()` uses local left-handed csys for 2d elements
Summary
Function SF::get_transformed_pts()
uses left-handed coordinate system (csys) for 2D-elements and right-handed csys for 3D-elements.
What version of openCARP are you using?
GIT hash: f8889b39.
What operating system and processor architecture are you using?
macOS Big Sur (11.6.2), x86_64
What is the current bug behavior?
SF::get_transformed_pts()
recalculates the nodal coordinates for 2d elements in a local csys and just copies the coordinates for 3d elements. The way it is set up right now, the local csys for the 2d elements is a left-handed one which leads to inconsistencies with the 3d elements where the coords are copied and output in the global (right-handed) csys.
What is the expected correct behavior?
Use right-handed csys for transformation of nodal coords for the 2d elements.
Possible fixes
Exchange y = cross(x, z)
with y = cross(z, x)
at
https://git.opencarp.org/openCARP/openCARP/-/blob/master/fem/slimfem/src/SF_fem_utils.h#L2163
and
https://git.opencarp.org/openCARP/openCARP/-/blob/master/fem/slimfem/src/SF_fem_utils.h#L2186