Examples: Updated external subdivision demo

[stevinz]

Description

Updated demo to use latest version of three-subdivide (v1.1.2)

Updates to library include:

• Use of params object to simplify calling
• Improved position and normal processing
• Support for morph targets (animation demo)
• Support for geometry groups
• preserveEdge parameter to enable preservation of mesh edges

Updates to three.js demo include:

• Subdivided geometries benefit from new library version, see screenshot below.
• Addition of lighting in scene and flatShading material property to help visualize normal processing.
• Dynamic material generation to accommodate rebuilding of materials.
• Fixed linting errors.

Live link:
https://raw.githack.com/stevinz/three.js/subdivide/examples/index.html?q=subdivision#webgl_modifier_subdivision

Screenshot: Position improvement
After (3) subdivisions, an icosahedron should resemble a sphere. Old version had noticeable, visible points.

[gpuido]

This is so underrated. Very cool. Any demo of preserveEdge and weights ?

[stevinz]

@gpuido Thanks!

There is a more complete demo on the repo for this library. This demo includes additional geometries for visualizing the preserveEdge option, as well as a slider for adjusting the weight.

The preserveEdge option can be visualized best with:

• Any 2D geometry (Circle, Plane, Ring, etc.)
• The 3D TeapotGeometry, noticeably the openings of the handle and spout.

Also, feel free to post any subdivision specific questions or issues directly on the external library repo.