PLY reader doesn't support user defined properties

See spec here: http://paulbourke.net/dataformats/ply/

PLY support user defined properties, the vtkPLYReader doesn't handle that currently.

changed title from PLY reader doesn't user defined properties to PLY reader doesn't support user defined properties

@utkarsh.ayachit What are your thoughts on whether this feature would impact Sandia?

....if you have folks using the PLY reader. Looking at the code, it should be a fairly simple fix. The format is quite simple really.

I looked, I do. Marked appropriately.

added project:sandia label

vtk/vtk!3941 (closed) may be of interest, @utkarsh.ayachit .

vtk/vtk!3941 (closed) has exactly this goal (ie. loading all nonlist PLY properties, that are point or cell related) But it was left out and the code quality is still below VTK standards. @nick.laurenson will have a new pass at it this week.

Please note that vtk/vtk!3941 (closed) also implement the functionalities in the writer, making unit tests much easier.