Lignes de champ magnétique

Visualize magnetic field lines from the Biot–Savart law for a steady current through a wire defined as a parametric curve (x(t), y(t), z(t)).

Field direction follows ∇×B (Ampère–Maxwell in magnetostatics); lines are traced by integrating along B/|B|. Wire and lines are shown in 3D with orbit, pan, and zoom.

Wire

Use t and Math.*. Enable closed loop to connect the last sample to the first (current loops). Presets include circle, helix, square loop, figure‑8, solenoid, and more.

Tips

Increase wire samples for smooth curves; soften singularities with softening ε. Current is in amperes (μ₀/4π scaling); magnitude mainly affects line density, not shape.