Ray-plane intersection
= Ray-plane intersection
{title2=$\lambda=\frac{n\cdot(a-o)}{n\cdot r}$}
Intersection of $o+\lambda r$ with the <plane> $n\cdot(p-a)=0$, when $n\cdot r\ne0$. For a <ray>, require $\lambda\geq0$. A zero denominator requires separate parallel or coplanar handling.