PyMVR Modification

[nrgsille76]

• add detailed xml declaration
• make fixture attributes of BaseChildNode optional
• make matrix of layer, groupobject, geometry3d and symbol optional.
  • Usually only one object has a matrix, mostly scene object, truss, etc.
  • It checks if the matrix is a default matrix and only writes the xml node if not.
• add Geometry3D to ChildList
• add ChildList to Symdef

[vanous]

• add detailed xml declaration - was resolved already previously in here
• make fixture attributes of BaseChildNode optional - was resolved already previously in here
• add Geometry3D to ChildList - resolved previously already in WIP branch in here
• add ChildList to Symdef - resolved previously already in WIP branch in here
• make matrix of layer, groupobject, geometry3d and symbol optional. Usually only one object has a matrix, mostly scene object, truss, etc. It checks if the matrix is a default matrix and only writes the xml node if not. - I agree with this, and i think we do not need this logic, because the MVR spec says, that the matrix can be 0 or 1, and if the matrix is missing, the default value is identity matrix, as per here, and the pymvr does this already by checking the matrix first, setting it as 0, which results in an identity matrix.

So i think we should be good here, hope i understood it all correctly. After i finish all work related to your code and our code, please let me know if all works as expected.