Hello, I have a height-field with non-uniform spacing. I want to compute the normals of the height-field. I used finite differences but want something more accurate. My height y = Sum from 1..n ( a * cos( b ) ) so I think I could differentiate this formula to get find the normals. y = Sum from 1..n ( a * cos ( b ) ) where a,b are constants y'' = Sum from 1..n ( -a * sin ( b ) ) What would the normal be? ( dy/dx, ..., dy/dz )? dy/dx = ( Sum from 1..n ( -a * sin ( b ) ) ) / dx dy/dz = ( Sum from 1..n ( -a * sin ( b ) ) ) / dz What should dx and dz be equal to since my height-field has non-uniform spacing? Thanks in advance!

The methods proposed means that I need to know my neighbouring vertices. Since I''m calculating my vertex position in a vertex shader, I have to do 4x the work ( need to calculate neighbour''s vertex position too ).