OptionalcolorOptionalformatFormat the measurement → label text. Receives the straight-line distance and the per-axis
delta (|b − a| on each axis). May return multi-line text or HTML; the default renders the
total plus a Δx/Δy/Δz breakdown. Old (distance) => string callbacks remain valid.
OptionallabelCSS class applied to the distance label, for styling.
OptionalsnapSnap to a vertex when the cursor is within this many screen pixels of it. Default 12.
Marker + line color. Default yellow.