Function rs_pbrt::core::geometry::nrm_dot_nrmf

pub fn nrm_dot_nrmf(n1: &Normal3f, n2: &Normal3f) -> Float

Product of the Euclidean magnitudes of a normal (and another normal) and the cosine of the angle between them. A return value of zero means both are orthogonal, a value if one means they are codirectional.