pixijs: Mesh examples are not working

The mesh examples on pixi’s v4 website aren’t working at all. It looks like they use PIXI.Geometry, which I believe is a construct from v5? You can look at http://pixijs.io/examples/#/mesh/triangle.js to see it broken.

Are there examples or tutorials out there on creating meshes within Pixi? Something that shows how to get from a very simple mesh created in blender/maya/3dsmax or from parsing an svg file to rendering it in Pixi would be of great help.