Control how many threads are used for the computation. Parallelization is possible if your license and hardware allow it.

The Parallelization Options dialog opens when clicking the Edit button and you can choose between Sequential, Parallel (Shared Memory), or Automatic Maximum of Threads.

Selecting Sequential will not apply parallelization and only one thread is used for the computation.

When Parallel (Shared Memory) is selected, the Number of Threads can be entered. Below, the Number of CPU Cores that the current machine has, the maximum number of Licensed Threads and the number of those licensed threads that are available (Available Threads) are shown in the dialog. Of course, the maximal number of parallel processes you can use, is the smallest of those three numbers.

If Automatic Maximum of Threads is selected, the number of parallel processes is automatically selected for optimal speed, based on the CPU cores and licensed parallel processes.

The Automatic Local Maximum of processes is automatically selected, which is the minimum of Number of CPU Cores, Licensed Threads, and Available Threads.

Under Surface Mode choose the Materials or Material IDs for which the surface area should be calculated. The surface is defined as the boundary between the chosen quantity and the rest of the structure.

Pore Space computes the surface of the pore space, which is the union of Pore and all Fluid materials. It returns the same result as All Solid Materials, which computes the surface of all solid and porous materials combined to one material. Please note that All Solid Materials does not include the inner surfaces between different solid Materials or Material IDs. For your convenience, all Material IDs which denote pore space are shown at the bottom of the dialog.

If Chosen Material is selected, choose the desired Material from the pull-down menu, listing all materials present in the structure, that appears below. This will estimate the surface area between the chosen Material and any other Materials.

If Chosen Material ID is selected, choose the desired Material ID from the pull-down menu that appears below. This will estimate the surface area between the chosen Material ID and any other Material IDs.

You can also estimate the surface between only two selected Materials or Material IDs. Choose the surface mode Between Materials or Between Material IDs and select the two materials or Material IDs to be considered for the surface area.

When selecting Periodic, the algorithm estimates the surface area assuming that the structure is periodic, so that the material that ends on one side of the volume reappears on the opposite side.

Observe the different results for the half sphere with radius 10 µm touching the domain boundary. The surface area of a half sphere with 10 µm radius is approximately 628 µm2 and the area of the circle from the cutting plane is approx. 314 µm2.

GeoDict uses two methods to estimate the surface are, counting voxel surfaces (algorithm 1) and using an algorithm provided by J. Ohser, F. Mücklich (algorithm 2). Find out more about the algorithms in the Results section.

When not checking Periodic, the staggered grid causes half a voxel to be cut off at the domain boundary. Thus, the counted voxels are those from the sphere surface and the cutting plane at the domain boundary, while the algorithm by J. Ohser, F. Mücklich corrects it to the area of the curved sphere surface.

If Periodic is checked, the spherical surface of the cutting plane is counted twice in algorithm 1, as it is additionally reached from the opposite domain boundary. The algorithm by J. Ohser, F. Mücklich for the real surface area corrects this doubled counted surface area because the half voxels on each opposite domain side are connected.