Dear Math2Market,

I heard that it is possible to rescale the simulation domain and the voxel size not only by integer values, but also by decimal numbers. Could you tell me how this can be done?
I would really like to run simulations faster this way, without losing too much accuracy.

All the best,
Caroline

Dear Caroline,

if you can do this depends on the origin of your structure model.

When you have all the analytic information (GAD data) of the structure (e.g. because it is the result of a FiberGeo - Create command),  you can use GadGeo - Edit Domain to rescale the whole model into a new voxel mesh. See https://geodict-userguide.math2market.de/2025/gadgeo_editdomain.html for details. This allows to rescale by non-integer factors.

When you import gray-value images in ImportGeo-Vol, you can also change the image resolution, and resample the gray values to a  new image with any given resolution.   

What you cannot do is to resample the voxel mesh with arbitrary factors. Here (in ProcessGeo), only integer values possible.

Regrads,
Jürgen

Dear Caroline,

in the case, that you only have a gdt-Structure, that you want to rescale, and that you have no gray value images or GAD objects, you can also use another method to rescale the gdt-structure by using ImportGeo-Vol.

• Import the original GDT-file (GeoDict will automatically detect the original voxel length)
• You need to use the Filter Image Size -> Scale
  
  • Re-sampled Length: enter desired target voxel length
  • Scale Function: It is important that you use the Scale Function “Nearest Neighbor” that this works properly.
  • More infos about the filter can be found in the User Guide of ImportGeo-Vol: https://geodict-userguide.math2market.de/2025/importgeo-vol_link.html
  
• Choose in “Segmentation & Labeling” -> Image Segmentation -> Global Thresholding -> Multiple Thresholds -> Number of Thresholds like the number of Material IDs that you had in your original structure minus one (example below was for 3 different material IDs)
  
• Press “Create Segmentation” and you are done

However, you need to be aware that this workflow can create unwanted artefacts, especially when you do a significant change in voxel length. Please check the structure after rescaling that it is still functional for you. If it is possible, it is better to do the re-scaling on gray value images when importing them into GeoDict, as Jürgen mentioned above.

Best, Roman