below text conetent,there is a term "LOA" at third line. What does the "LOA" mean? We extend the classic 1D toon texture by adding a vertical “detail” axis (corresponding to LOA) to build a 2D toon texture. The horizontal axis corresponds to tone as in a classic toon texture – the texture coordinate along that axis is derived from a standard lambertian shading computation: n · L, where n is the unit surface normal and L is the unit light direction.