Variable normal offset
= Variable normal offset
{title2=$P_d(u,v)=P(u,v)+d(u,v)n(u,v)$}
A <variable normal offset> displaces a <parametric surface> along its unit <normal vector> by a scalar field $d(u,v)$. Unlike a constant-distance <parallel surface>, its derivatives also contain $d_u n$ and $d_v n$.
// Target: analysis.bigb