Narrow pairs of chains with same convexity are not rounded. Two or more chains are considered to be narrow if the rounds created on them intersect each other.

Each chain in a narrow pair of chains is rounded under different Auto Round members. However, if a model contains a narrow pair of chains with different convexity, the convex chains are rounded first.

The following figure shows the model after the round operation is performed on the narrow pair of edges with different convexity.

The Auto Round feature does not round edges of the same convexity but that share a vertex with a chain that belongs to a narrow pair of chains. Rounding such edges may cause problems while rounding other edges.

In the above illustration, the non-narrow pair of chains is not rounded as these edges have the same convexity but share a common vertex with the narrow pair of chains.