Dilate performs the morphological operation dilation on the selected material ID (Dilate Material ID) by the number of voxels (or the thickness) entered in Dilate by....

The dilation appears as a coating in the selected Coating Material ID.The coating material can be selected to be the same as the material to dilate, for example to increase the diameter of fibers or grains in the structure.

When checking Only Reassign and choosing a material ID from the pull-down menu (e.g. ID 02), only voxels of this material ID (here: grey) are replaced by voxels of the Coating Material ID (e.g. 03, here: blue). This occurs only for grey voxels located at a certain distance or less (defined in Dilate by…, e.g. 5 voxels) from voxels of the Dilate Material ID (e.g. 01, red). The blue coating (03) appears only on some of the grey grains.

When the Dilate Material ID is changed to 02 (grey) and the Only Reassign is chosen to be 01 (red), the blue coating (03) appears now only on some red grains.

For periodic 3D-structure models, Periodicity can be applied either in X-Direction, Y-Direction and/or Z-Direction. Checking none of the directions means that the structure is cut off at the boundary. For example, compare the effect of dilating periodically in all directions. When periodicity is applied, the blue coating of the red fiber continues on the opposite side of the domain (see the blue spot on the left side).