Archive export mode is triggered when the user wants to export render archives to be rendered using a standalone version of the rendering engine, outside of the Softimage interface.
This mode is only called if the renderer plug-in registered itself as archive export capable by adding siRenderProcessExportArchive to Renderer::PutProcessTypes, and registering an archive file format with Renderer::PutArchiveFormat.
Since the archive is meant to be rendered outside of Softimage it is important that the renderer plug-in include all information required to do so, since it is impossible to request any missing information from Softimage later on.
