[Smtk-developers] Question about tessellation info

[David Thompson]

Hi all,

I've pushed changes to the smtk/model/Tessellation class *and* the test data repo. The JSON storage for tessellation information has changed. It is mostly compatible with ThreeJS but extends the format to include support for polylines and vertex cells. Be aware that any JSON files you have outside of the SMTKTestData repo will probably cause trouble for the modified vtkModelSource/vtkModelMultiBlockSource classes.

Yumin, I've also updated the discrete bridge to take advantage of the new tessellation format... please verify that it works for you in ModelBuilder.

	David

> Yumin has pointed out that some VTK cell types (quads, polygons, polyvertices, polylines, triangle strips) are not supported in SMTK's Tessellation structure yet. I am working on adding support for them but have a couple of ways to proceed:
> 
> 1. Keep things compatible with Three.js' model format ( https://github.com/mrdoob/three.js/wiki/JSON-Model-format-3 and https://github.com/mrdoob/three.js/wiki/JSON-Geometry-format-4 ) at the expense of increasing storage by forcing some cell types (polygons, polylines, polyvertices, triangle strips, but NOT quads) to be converted into multiple entries in smtk::model::Tessellation.
> 
> 2. Add some non-Three.js-compatible connectivity entry types to keep things VTK-compatible. This would be slightly more efficient for some cell types in the vtkSMTK classes for desktop display via VTK.
> 
> Any opinions?
> 
> 	Thanks,
> 	David