Over the years I haven't used .obj files very much so know little about them.

But I've come across something I find interesting. I don't know if this is a limitation of the Houdini File Cache Node saving out .obj files or something inherent with the .obj file format itself.

In the attached hip there is two Tube SOP Node examples.

One has it's columns set to 12 and the other set to 2000.

They are also followed by a PolyFill SOP Node with Fill Mode set to 'Single Polygon'.

With the first example,(12 columns), the File Cache saves out as .obj with no issues.

However, with the second example (2,000 columns), Houdini gives an error when saving out with File Cache Node and also only shows the Tube geometry without the 'caps' the PolyFill Node had originally created.

It's like .obj(or file cache node) can't handle single polygons that have too many pts associated with it.

Of course, changing the Fill Mode to something like triangle fan resolves the 'issue';

But this is interesting on why it can't for a Single Polygon having many points.