\( G(x, y) \) – noise value at point \( (x, y) \)
\( w_i \) – weight
\( \mathrm{grad}(p_i, x, y) \) – dot product of the gradient at grid point \( p_i \) toward \( (x, y) \)
\( n \) – number of surrounding grid points
\( V(x, y) \) – noise value at point \( (x, y) \)
\( p_i \) – randomly placed points
\( d(p_i, (x, y)) \) – Euclidean distance between \( p_i \) and \( (x, y) \)
$$S(x, y) = \mathrm{interp}\left(v_i, w(x - x_i, y - y_i)\right)$$
\( S(x, y) \) – value noise at point \( (x, y) \)
\( v_i \) – random value assigned to grid point
\( w \) – interpolation/smoothing function
\( \mathrm{interp}(...) \) – interpolation between values