The short version: everyone was right. Induction caused massive AC on the sensor data wire.

I added a makeshift low-pass power filter with a resistor and capacitor I had handy in my tool bin, and it solved the sensor issue.

Turns out, 25 meters of narrow gauge wire is a terrific antenna.

I need to do a proper measurement of the AC frequency on the power rail and design an RC filter to match it for the production design, but this is good enough for now.

Learning to make slow movements look natural. It’s slow going.

And with a cat:

Next up in terms of goals is to see how to make the sprite slow and stop naturally, and then accelerate back up to travel speed.

Witch Lights Animation Test 2: Slow, stop, go:

I've spend a few iterations tuning this. The deceleration curve is fairly decent, but it doesn't look right when it starts up from a hard stop. I think the sprite should "wind up" before going, so that means backing up a bit. I'll have to play with the timing to make it look right.

Once I have these dialed in, I can break them up into "intro" and "outro" animations, and create some loop animations to put in between.