The Mark Enclosed Elements option uses Material Points within an enclosed volume of surfaces to mark all the elements within that volume and assign them to the same Volume Part as the enclosed Material Point. Only mesh in regions containing the selected Material Points will be affected.

Any elements within the enclosed space containing the Material Point are placed into the same Volume Part. If the Material Point is outside of the selected surfaces, then all elements with centroids outside of the enclosed surfaces are placed within the Volume Part. If there is an enclosed volume that does not contain any material points, its elements are not affected.

The end result is similar to that obtained using Flood Fill, but the approach is less restricted because the mesh does not need shells or faces aligned with the enclosing surfaces. For most situations, Flood Fill is a more robust and faster method. For situations where the mesh is not surface fitted, this option should be used in place Flood Fill.

In Figure 441: Example of the Mark Enclosed Elements Option, note that the elements are marked based on the location of the centroid of each element. Note also that the region between the cylinders is an enclosed volume but has no Material Point, so its elements remain with the original material.

Figure 441: Example of the Mark Enclosed Elements Option