For structured grid entities, the normalized turning angle is calculated in the selected computational direction.

The Smoothness function is a point based measure. Fidelity Pointwise computes the angle turned while traversing three adjacent coordinates: index-1, the current IJK, and index+1 in the computational direction chosen. A value of 1 indicates there is no turn, or the three points are colinear. A value of 0.5 indicates a 90 degree turn. And a value of 0 indicates a 180 degree turn, or the grid is folded onto itself. Furthermore, this function will be calculated across entity boundaries as long as the adjacent entities are loaded into Examine as well. Otherwise, the value at boundaries will be set to 1.

Since this function is directional along computational coordinates, adjacent entities must be computationally aligned in order for reference surfaces to exhibit a continuous variation in the function across entity boundaries. Nonaligned entities will display a discontinuity across their common boundary. Block adjacency is determined by block connections using a common boundary.