•Generate unit
vectors (a, b) at each integer lattice point (ix, iy)
–Use zero
intensity at each lattice point.
•For a
non-integer evaluation point (x, y) determine
the 4 nearest integer grid points.
•For each integer
grid point (ix, iy), find the fractional
value of the vector (fx, fy) from (ix, iy) to (x, y, z) and take its dot product with the gradient vector at that integer point (ix, iy).
•Interpolate
the 4 dot-product values to compute the noise value at the grid point
•This has more
high-frequency energy than value
noise.