Generates a SPDL file to describe a Softimage object. This is a low-level API. Normally
this method would be used to install a CustomProperty or CustomOperator that
has been created in memory. In this circumstance, the purpose of a SPDL file
is to remember the PPGLayout, and the logic code between Softimage sessions.
If the CustomProperty is only used in a temporary fashion then it is not necessary to
use a SPDL file, but if the CustomProperty will be saved in a scene file this is necessary.
Softimage will not use the newly created SPDL file until XSIUtils.RegisterSPDL is
called.
Any existing file is overwritten. If there was an existing SPDL file and it
was associated with a different type of object then the installation of Softimage may be damaged.
This method can be used to write out the SPDL file for a built-in operator.
When writing out SPDL file for operators the GUID identifying the operator and the GUIDs use in the parameter
definitions will always be re-generated when the SPDL is written. This is to ensure that there's no
conflict with an installed or in-use operator.