smoothNormalAngular
Evaluates a normal at rectified t such that it is rotated towards the normal of the neighbouring segment when t lies within radius (in arc length) of a corner formed by a segment join.
Unlike smoothNormalLinear the normal is interpolated by angle, and the blend weight follows a smoothstep curve, such that the normal eases in and out of the blend region. At cusps (corners turning by 180 degrees) the normal rotates around the tip of the cusp.
When t falls exactly on a corner the returned normal is the angle bisector of the normals of the two segments. The effective radius around a corner is limited to half the length of each of the two adjacent segments, such that blend regions of neighbouring corners never overlap.
Parameters
rectified t-value
blend radius in arc length