(2019-07-29, 19:30)Roland Melkert Wrote: The matrix in the type 1 lines always works with the abs origin (0,0,0) of the part/submodel it references.
To add to that, for the most part, each part has an origin that is believed to be the logical place for the origin to be for that part. This will rarely be the center of the part. If you load a part in LDView, and enable the "Show Axes" option in the Miscellaneous section of the General preferences page, you will see where the origin is for that part. For those axes, bright red is positive X, dark red is negative X, bright green is positive Y, dark green is negative Y, bright blue is positive Z, and dark blue is negative Z.
Also, note that "up" in LDraw files is along the negative Y axis, and that LDraw's coordinate system is left-handed instead of right-handed like in most 3D formats.