1) Reworked logic for pasting volumes
2) Fixed paste of volumes into different objects
3) Do not apply offset when pasting into the copied object
4) Keep source transformation matrix and relative positions when copy/pasting volumes into another object
Ulocking the "anisotropic" scaling checkbox will bake the transformation
into meshes to allow for scaling in world axes.
Optimized and templated the stl_transform functions, now also available for 3x3 matrices.
The Canvas3D::reload_scene() now maintains selection even if all volumes of an instance changed their IDs.
is_left_handed() method on transformations and volumes
rendering of GLVolumes in left handed coordinate systems by glFrontFace(GL_CW);
SLA slicing on left hand oriented instances by flipping the mesh for SLAPrintObject in X.
rendering of the SLA cutting plane in left handed systems
resetting the SLA clipping planes on 3D preview invalidation
Sphere and Cylinder are scaled to the same volume as Box
Newly entered modifier meshes are rotated parallell to the world coordinates.
If the instance coordinate system is rotated and scaled, it is not possible
to create an unskewed modifier to world transformation. In that case
the best possible transformation is found to minimize least squares error
of the 8 corners of the new modifier mesh bounding box using
Levenberg-Marquardt algorithm.
FIXME:
1) The Levenberg-Marquardt non-linear least squares does not converge
nicely, it may require some tuning.
2) Above all, if 1) is called, then often the skew of the modifier mesh
is so high, that it is likely more useful to display the modifier
with zero rotation and inverse scaling, so that the modifier will be
of correct size, but not parallel to the world coordinates.
