Through the Material ID Mode, select between applying the Material ID based on the materials or the types of objects present in the structure.

If Resolve Overlap is checked, the overlap of objects is not assigned to a new material ID. Instead, the water-shed algorithm is used to decide which of the overlap voxels belongs to which object in a post-processing step. Thus, each overlap voxel is assigned to one specific object. This option needs more memory and a longer run-time.

In detail, the Resolve Overlap algorithm starts with computing a distance map for the overlap voxels, i.e. it computes the distance to the next object for each overlap voxel. On this distance map the watershed algorithm is run using all voxels belonging to an object as seeds. There, all voxels contained in the same object have the same material ID. Thus, the overlap area is filled with the object IDs according to the distance map.

To mark the contact voxels between the objects with a separate material ID, select Mark Contact Voxels and choose a Contact Material from the Material Data Base.

The voxels, where two or more objects IDs meet, are marked as contact voxels, by reassigning them with a new material ID. Thus, the layer of contact voxels always has a thickness of two voxels.

In the following observe the resulting Material IDs for the overlap for not resolved, resolved and resolved overlap with marked contact voxels, while all other settings are kept the same.

Default Overlap Material controls the material assigned to the regions where objects of the generated structure overlap. The material ID of these regions is chosen by default as the next available material ID. The color settings and the constituent materials can be changed for each Material ID.

Overlap rules can be set to control how the overlap between materials should be handled in the structure. You can set up to 100 rules by selecting a number in the box for Number of Overlap Rules, and then define these rules in the panel below.

The materials shown in the panel (as buttons or pull-down menu) correspond to the material selected under the Object Options tab.

For example, you simulate a structure made of plastic fibers that melt together using a negative isolation distance as a generation and overlap mode under the Create Options tab. Then, you can set up a rule that defines what happens with the material ID at the melting location.

In the example shown below, three rules have been defined: The overlap of objects with material ID 1 (dark gray) will be assigned to ID 3 (light gray). The overlap of objects with material ID 2 (yellow) will be assigned to ID 4 (orange) and the overlap of ID 1 and ID 2 will be assigned to ID 5 (blue). For all other possible overlap cases, the Default Overlap Material ID is applied.

Note, that the results for volume in the resulting report do not change for different overlap rules, as the values are computed before the post-processing is applied.

In the three examples given for Resolve Overlap, the Absolute object distribution is shown below.

For the volume percentages of the final structure, refer to the Statistics in the left of the GeoDict main window. Either just hover over the statistics bar or unfold the Statistics section in the project status panel below.

Here, the volume statistics are shown for the example with default overlap rules. The red fiber has 3.55 % of the volume, the gray fiber has 5.81 % and the overlap 1.73 %.

In the result file the overlap volume is proportionally added to the volume of the overlapping fibers. Here, the red fiber obtains 3.55% + (1.73/2)% = 4.415%. Rounded, this results in the 4.42 % shown in the report.