A PR for this was initially opened here but the change was rolled back since it required a few more changes outside the scope of the PR (CesiumGS/cesium#9063 (comment)).

I believe this is all the changes required:

• In EasingFunction.js, change QUADRACTIC_IN, QUADRACTIC_OUT, QUADRACTIC_IN_OUT to the correct spelling
• Update the spec in `TweenCol

Issues:

The repo use text-encoding lib in the utils https://github.com/uber/xviz/blob/master/modules/parser/src/utils/text-encoding.js#L18

text-encoding is deprecated and no longer maintained. Nodejs expose TextEncoder from util module in v8, and from global module in v11.
https://nodejs.org/api/util.html#util_class_util_textencoder
https://www.npmjs.com/package/text-encoding

I was looking into correctly binding PointCloudLayer properties with PointsMaterial, to avoid having (beside a few other things) this part. This resulted in a bigger challenge than I thought, because we have a few properties that already have definition. I can cite opacity