I'm using Helixtoolkit in my WPF project and it seems that Helixtoolkit doesn't support FBX files. So I think I should use the 3D model import-export library Assimp. how can I import an FBX file into my WPF project using HelixToolkit.Wpf.SharpDX.Assimp ? There is no documentation for Assimp.