Conversion from IPT to PLY is not supported yet :(

An IPT file extension is used for Autodesk Inventor objects.

Autodesk Inventor is a CAD application that engineers and product designers use to construct prototypes of mechanical products. These prototypes, referred to as assemblies, consist of several individual parts joined together. Each Inventor part is saved in an IPT file.

Inventor users can import IPT parts from outside the program or create their IPT parts using the Inventor's part design tools. Typically, users begin by creating a 2D drawing of a part before transforming that drawing into a 3D model. Thus, an IPT file may contain either a 2D or 3D object. Files in IPT format can be opened using Autodesk Inventor 2017, Autodesk Inventor View 2017, Autodesk Fusion 360, and SpaceClaim Engineer.

PLY is a computer file format known as the Polygon File Format or the Stanford Triangle Format. It was designed to store three-dimensional data from 3D scanners. The data storage format supports a relatively simple description of a single object as a list of nominally flat polygons.