Actually the issue seems to be different from what I thought. It still happens when I start from scratch in 3.4.0.
- Turn on Additive Drawing
- Draw a line at frame 1 – edit line to have only two points
- Advance to frame 3
- Extrude the line to have a third point (using E hotkey)
- Repeat the process a few times to extend the line
If I then step backward on the timeline, I always see junk at the end of the line. If I look carefully in edit mode, it seems that each extrusion actually produced 2 points at exactly the same location. If the duplicates are carefully deleted/dissolved (at each keyframe), then stepping looks clean. Mysterious.
Basically I am trying to imitate something like a Build modifier, but on a stroke.
