* Add "setPartsLibraryPath" function

* Add "preloadMaterials" function

* Use single material if possible

* Fix normal smoothing

* Add smarter subobject cache

* Remove static scope stack

* Make "processObject" async

* fix process order

* Fix construction steps

* comments, variable rename

* arrow functions to classic functions

* Clean up

* Added vertex tangent support

* Add "setPartsLibraryPath" function

* Add "preloadMaterials" function

* Use single material if possible

* Fix normal smoothing

* small improvements to normal performance

* use arrays to store vertices

* remoe extraneous line

* Use typed arrays when generating geometry

* remove unused import

* Fix re-declared variable name

This reverts commit 721bf748.

* small improvements to normal performance

* use arrays to store vertices

* remoe extraneous line

* Use typed arrays when generating geometry

* remove unused import

* Iterate over vertices

* generalize vertex transformation

* generalize smooth normals to vertex array length, fix normal application

* Fix re-declared variable name

* remove pre-splitting of quads

* normal fixes

* improve normal shading

* triangles -> faces

* remove full half edge list

* Clean up

* Promote .ior to a material property

* Clean up

* Simplify encoding logic

* Clean up

* Remove outdated support for ENVMAP_TYPE_CUBE

* Clean up

* Update screenshot

* MeshPhysicalMaterial: Fix refraction

* Update screenshot

* GLTFExporter: Added KHR_materials_transmission and KHR_materials_volume support.

* GLTFExporter: Clean up.