Adaptive Sizing can be thought of as a 2D curvature and proximity-based refinement approach which refines edges based on curvature and/or proximity but does not propagate the refined mesh along the face. It works with Resolution, Span Angle Center and Transition, and has historically been used as a way to reduce the total element count while capturing every edge of the model. This approach can significantly stretch the mesh leading to poor mesh quality, so it is generally recommended to use one of the other sizing options and use defeaturing to reduce the total element count when needed.

When Use Adaptive Sizing is set to Yes, the mesher uses the value of the element size property to determine a starting point for the mesh size. The value of the element size property can be set by the user or automatically computed using Defaults. When meshing begins, edges are meshed with this size initially, and then they are refined for curvature and 2D proximity. Next, mesh based defeaturing and pinch control execution occurs. The final edge mesh is then passed into a least-squares fit size function, which guides face and volume meshing.