Stefan Röttger MedicalVisualization/Iso Line Edge Intersection

Iso Line Edge Intersection

The intersection point on one edge of cell with the iso line is computed as follows:

Let $s_1$ and $s_2$ be the scalar values of the edge’s end points $\vec{x_1}$ and $\vec{x_2}$ , respectively. Let $v$ be the iso value to be extracted.
There is an intersection point $\vec{p}$ if $(s_1 < v \land s_2 \ge v) \lor (s_1 \ge v \land s_2 < v)$ with
$\vec{p} = (1-w)\vec{x_1}+w\vec{x_2}, w=\frac{v-s_1}{s_2-s_1}$