You will find a Maya scene file available for download here, which will be an example scene featuring eyelids with both LINEAR deformations (created using the traditional blendshapes editor) and NON-LINEAR deformations (achieved using Bifrost nodes).
Additionally, you will find a tutorial about creating a Non-Linear Interpolation using Bifrost Graph Editor in Maya.
Thanks for watching and I hope you enjoy!
Cheers!
Alexandre Alin
3D Character Artist/Co-Founder at Renart Studios