The Rescale Structure operation changes the resolution of a structure, which means the voxel number and the voxel length are changed, while the physical size of the structure stays the same. The voxel count in the domain is changed according to the entered Grow Factor (increase number of voxels) or Shrink Factor (decrease number of voxels), while the voxel length is changed accordingly (decrease for Grow and increase for Shrink). Thus, there is a smoothing of the structure when applying Grow Rounded or Grow Strictly, and a coarsening when applying Shrink.

Rescale Options

Three Rescale Modes are available to rescale the structure:

• Grow Rounded, which is always applied with a Grow Factor of 2,
• Grow Strictly, that accepts any positive integer as Grow Factor (for example 3),
• Shrink, which is always applied with a Shrink Factor of 2.

The Grow Factor or Shrink Factor is shown below the Mode panel, for the mode Grow Strictly change the value here.

Below, the New Voxel Length (in meters) after the rescale is displayed as information.

Check Rescale Volume Fields to apply the rescaling to the volume fields that are currently loaded in GeoDict.

How do the Rescale Modes work?

The different rescaling processes are illustrated in the example below, considering a group of four voxels. The red squares represent solid structure voxels, and the white squares represent empty background voxels.

In the Grow Rounded method, 23 voxel with the same ID are created from each voxel (voxels are doubled per direction). Then, the neighboring voxels (common faces, edges, and vertices, including the voxel itself) are compared and the majority of Material IDs will be assigned to this voxel. If possible, the analytic data is used for Grow Rounded to achieve even better results.

Grow Strictly discards the analytic data instead as only the first step of the grow rounded algorithm is performed (doubling the voxels).

The Shrink method reduces 23 voxels to one voxel, where the majority of the previous Material IDs will be used for the new voxel. In case of equality, the solid Material ID is preferred over the "empty" pore Material ID.

Example

We illustrate the effects of the different rescaling methods on a structure which contains spheres and ellipsoids. The best way to observe the visual effect of rescaling is to use the 3D visualization (select View → 3D Rendering in the menu bar or click the icon in the toolbar) and set the Structure Renderer to Box.

With the Grow Round mode, the voxel size is divided by 2 (now 0.5 µm) and the domain doubles in each direction (now 320x320x320 voxels). To further (visually) smooth the objects in the structure by rounding, do further Rescaling as needed. Moreover, observe that the GAD Data is maintained.

In the Grow Strictly mode, you can see no visual smoothing effect of the structure, but the domain size and voxel length have changed as before. Also, in contrast to the other method, the GAD data is lost.

In the Shrink mode, the GAD data is maintained and the domain size is half of the original size in each direction (now 80x80x80 voxels), while the voxel length is doubled (now 2 µm).