By Adam Nagy
Depending on what your entity is derived from, UCS >> OBject tries to get the UCS from the entity in different ways. If your entity is derived from AcDbEntity and it does not provide a NEAR snap point through getOsnapPoints(), then getEcs() will be called.
One thing to note is that the origin will be further transformed, which we can counter act so that if _ecs in the below example contains the exact coordinate system that we want, we can transform it before passing it back:
void MyEnt::getEcs(AcGeMatrix3d& retVal) const
{
assertReadEnabled();
// UCS >> OBject will do an
// orig.transformBy(AcGeMatrix3d::worldToPlane(normal));
// so we'll do here the reverse
AcGeVector3d x, y, z;
AcGePoint3d orig;
_ecs.getCoordSystem(orig, x, y, z);
orig = orig.transformBy(AcGeMatrix3d::worldToPlane(z).invert());
AcGeMatrix3d mx;
retVal = mx.setCoordSystem(orig, x, y, z);
}
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