Physics
Standing Wave (n = 3)
y = 2A sin(nπx/L) cos(nπvt/L)
The third harmonic of a clamped string: the nodes stay pinned while the antinodes swell and collapse together.
Computed & rendered in pure C# on the frozen OnlyCSharp 1.8 library — animation baked to GIF with the library's own
Gif encoder (no GPU, no ffmpeg, no external packages).