A wonderful example of this is:

The Continuity of Splines https://www.youtube.com/watch?v=jvPPXbo87ds

and

The Beauty of Bézier Curves https://www.youtube.com/watch?v=aVwxzDHniEw

by Freya Holmér https://www.youtube.com/@acegikmo

While not animated, I find:

_Euclid's Elements_ (Joyce's Java Version) very helpful https://mathcs.clarku.edu/~djoyce/java/elements/elements.htm...

Since my current project has pretty much devolved to putting a UI on various trigonometric functions and allowing the user to program them, I'd be very glad of other resources in this space (currently working through Hilbert's _Geometry and the Imagination_ and the book which matches https://projectivegeometricalgebra.org/ and just finished the _Make:Geometry/Trigonometry/Calculus_ series, and have had recommended Curves and Surfaces for CAGD: A Practical Guide by Gerald Farin)

Freya Holmér is great.

To add on: Grant Sanderson's 3Blue1Brown youtube channel might be the best conceptual math presentation in history, the animations are incredible.

Desmos also produces curriculum for K-12 (Desmos Classroom) that takes advantage of the computer’s ability to give real-time feedback for student answers beyond just giving them a binary correct/incorrect. It shows them what their wrong answers really would mean in the little animated scenario. Good stuff!

https://danmeyer.substack.com/p/the-only-question-you-need-t...

How can we animate in Desmos?

I'm trying to animate t in a parametric curve (Lissajous) (sin(2*t*PI), sin(t*PI))

Example Lissajous animation https://ericfortis.github.io/lissajous/