Animation

[ikeough]

BACKGROUND:
We're starting to work on stories in Hypar, and one of the stories we are often asked to tell is how things are installed. The most effective way to tell this story is an animation.

DESCRIPTION:
This PR adds GeometricElement.Animation property. The animation is added to the geometric element because it is associated with the animation of the element's transform.

FUTURE WORK:

• Animations do not serialize to JSON.
• Animations have linear interpolation currently. We can add support for cubic spline and step interpolation in the future.
• Animations all have the name prefix animation_ (see video). There isn't an obvious way to change this.
• This changes our transforms in glTF from using matrices to using translation, rotation, and scale, because animations animate each of these channels separately. To do this, we use the Animation class uses the System.Numerics quaternion implementation which is more fully-featured than our own. It's possible that we could move matrices and quaternions to System.Numerics.

REQUIRED:

• All changes are up to date in CHANGELOG.md.

Screen.Recording.2022-08-31.at.1.20.01.PM.mov

---

This change is