Hi @Cocojambo
I encountered the error as well after I upgraded babylon version.
this.bjsRECAST.Vec3 is not a constructor
I used to only need this line before creating the RecastJSPlugin instance.
window.Recast = require('recast-detour');
After upgrading babylon version, I had the error above. Now I need to do the following to fix the error.
window.Recast = require('recast-detour');
window.Recast();