gltfInterpolation top-level property
Implementation
var gltfInterpolation = {
"CUBICSPLINE": null, // We use a custom interpolant (GLTFCubicSplineInterpolation) for CUBICSPLINE tracks. Each
// keyframe track will be initialized with a default interpolation type, then modified.
"LINEAR": InterpolateLinear,
"STEP": InterpolateDiscrete
};