Convert a greyscale heightfield buffer into a tangent-space normal
map buffer via central-difference gradient. strength scales the
gradient (higher values produce more pronounced relief). The
gradient lookup wraps at the buffer edges, so the output tiles
seamlessly when the input does.
Convert a greyscale heightfield buffer into a tangent-space normal map buffer via central-difference gradient.
strengthscales the gradient (higher values produce more pronounced relief). The gradient lookup wraps at the buffer edges, so the output tiles seamlessly when the input does.