3D models (or rather their geometry) saved as polygon files (.ply) can be usally exported to other 3D models or geometry files, including .pts files. This can be done for example in programs like Meshlab, which you can download for free from SourceForge.
Convert Polygon graphics to PointCloud 3D file.
We have found 2 software records in our database eligible for .ply to .pts file format conversion.
Microsoft Windows software - convert ply to pts on Windows
A 3D CAD translation softwate
Convert from ply file format
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned ply to pts. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
Multiplatform software - convert ply to pts on any platform
An open source system for 3D triangular meshes