Drag mouse to rotate model.
Hold shift key or use mouse wheel to zoom it (canvas is matched to the
browser window). Uncheck path to see 3D wave.
The script makes 2 it time steps dt per frame.
FHN model. Dynamics of a scroll bended in a ring on 128x128x64 grid.
For ε = 0.1 it contracts (positive tension) and for
ε = 0.5 it enlarges (negative tension).