Hello,
I imported CT TIFF images of a fibrous catalyst layer into GeoDict and successfully reconstructed the structure.
However, I have a problem with the visualization.
The pore space is displayed as a white phase, so the internal fiber structure cannot be seen clearly.
I would like to know if it is possible to:
・make the pore space transparent,
・hide the pore phase completely,
・or directly visualize only the fiber structure inside the reconstructed model.
Could you please tell me how to change these visualization settings in GeoDict?
I attached an image showing the current problem.
Thank you very much for your help.
Hello Shunsuke,
You can change the appearance of any material (including the pore space) directly from the
Color & Visibility panel that is located on the right‑hand side of the GeoDict user interface. Below is a quick walk‑through of the most common options you mentioned.
Hide the Pore Material Completely- Open the Color & Visibility panel (second entry in the sidebar).
- Find the row that corresponds to your pore phase. In your case it is ID00 Pore.
- Uncheck the Visible checkbox next to that row. The pore volume will no longer be shown, so you will see only the fibers.
Tip: If you still see a gray background after doing this, you're probably looking at the CT images volume field that GeoDict keeps after segmentation. In the
View Controls →
Volume Field section, uncheck the Volume Field box to turn it off.
VisibilitySettings.png
Make the Pore Material Transparent- In the View Controls panel, expand the Structure tab.
- Choose Transparency Mode → either Volume (entire materials) or Surface (only the material boundaries).
- Click the Edit button below.
- In the dialog, set the transparency slider for the Pore phase to the desired value (0% = fully transparent, 100% = fully opaque). Click Apply.
Transparency.png
Additional Visualization Options- Shadows: Go to Camera (in View Controls) → enable Shadows.
- There are also other lighting options under the same tab.
- Background: You can change the Background Color in the Color & Visibility panel.
More HelpFor a deeper dive into all available visualization features, consult our GeoDict User Guide:
https://geodict-userguide.math2market.de/2025/visualization.html (https://geodict-userguide.math2market.de/2025/visualization.html)
Best regards,
Jonas
Hello,
Thank you very much for your kind and detailed answer to my previous question.
I was able to solve the visualization problem successfully.
I have another question regarding the structural analysis capabilities of GeoDict.
My research focuses on understanding the structure of fuel cell catalyst layers.
I imported CT images of an actual fibrous catalyst layer into GeoDict and reconstructed the 3D structure.
I would like to analyze the reconstructed catalyst layer in GeoDict and evaluate structural properties related to mass transport and morphology, such as:
diffusivity,
tortuosity,
bottleneck diameter,
pore size distribution,
and other structural parameters.
My questions are:
What kinds of structural or transport properties can be evaluated from reconstructed CT structures in GeoDict?
How many different material properties can GeoDict calculate for this type of porous structure?
How accurate are these calculated properties compared with experimental measurements or real structures?
I am especially interested in evaluating transport characteristics inside fibrous catalyst layers for fuel cell applications.
Thank you very much for your support.
Hello Shunsuke,
you can compute a wide variety of material properties with GeoDict. Below I have listed the modules that are directly related to the properties you mentioned and added brief notes on other modules that might interest you for fuel cell applications. I recommend reviewing the corresponding sections of our user guide to get a full picture of what is possible.
DiffusivityDiffusion can be simulated with our module
DiffuDict (located under Predict). In general this allows you to simulate the net movement of molecules or atoms from a region of higher to lower concentration.
More information: https://geodict-userguide.math2market.de/2026/diffudict.html (https://geodict-userguide.math2market.de/2026/diffudict.html)
TortuosityFor the computation of the tortuosity there are many different approaches based on geometric or physical properties of the sample. All available approaches for calculating tortuosity are combined in the
Compute Tortuosity GeoApp (located under GeoApp → General GeoApps → Geometric Properties → Compute Tortuosity).
More information: https://geodict-userguide.math2market.de/2026/geoapp_computetortuosity.html (https://geodict-userguide.math2market.de/2026/geoapp_computetortuosity.html)
Bottleneck Diameter & Pore Size DistributionThese properties are computed with
PoroDict (located under Analyze), which offers several options for pore size distributions, percolation paths, and more.
More information: https://geodict-userguide.math2market.de/2026/porodict.html (https://geodict-userguide.math2market.de/2026/porodict.html)
Other structural parameters- AddiDict: Simulate particle, molecule, or concentration transport and adsorption
https://geodict-userguide.math2market.de/2026/addidict.html (https://geodict-userguide.math2market.de/2026/addidict.html)
- MatDict: Compute material properties of the solid phase such as surface areas
https://geodict-userguide.math2market.de/2026/matdict_materialcharacterization.html (https://geodict-userguide.math2market.de/2026/matdict_materialcharacterization.html)
- FiberFind: Identify fibers and obtain statistics such as orientation, diameter, or length
https://geodict-userguide.math2market.de/2026/fiberfind.html (https://geodict-userguide.math2market.de/2026/fiberfind.html)
- ConductoDict: Compute effective conductivities
https://geodict-userguide.math2market.de/2026/conductodict.html (https://geodict-userguide.math2market.de/2026/conductodict.html)
- FlowDict: Simulate fluid flow and obtain properties like permeability or pressure drop
https://geodict-userguide.math2market.de/2026/flowdict_link.html (https://geodict-userguide.math2market.de/2026/flowdict_link.html)
- ElastoDict: Compute mechanical properties and simulate deformations
https://geodict-userguide.math2market.de/2026/elastodict.html (https://geodict-userguide.math2market.de/2026/elastodict.html)
- SatuDict: Simulate two phase fluid systems, saturation, and related properties
https://geodict-userguide.math2market.de/2026/satudict.html (https://geodict-userguide.math2market.de/2026/satudict.html)
Accuracy of calculated propertiesA comparison of simulated and measured permeabilities and diffusivities for a gas diffusion layer is presented in the following publication:
Becker, J., Flückiger, R., Reum, M., Büchi, F. N., Marone, F., & Stampanoni, M. (2009). Determination of Material Properties of Gas Diffusion Layers: Experiments and Simulations Using Phase Contrast Tomographic Microscopy. Journal of the Electrochemical Society, 156, B1175–B1181. https://doi.org/10.1149/1.3176876Additional studies on fuel cells that employ GeoDict can be found here: https://www.math2market.com/showroom/scientific-publications.html?industry=fuel-cells (https://www.math2market.com/showroom/scientific-publications.html?industry=fuel-cells)
Additional resources- Our website: https://www.math2market.com/industrial-solutions/fuel-cells.html (https://www.math2market.com/industrial-solutions/fuel-cells.html)
- Our YouTube channel, in particular:
- https://www.youtube.com/watch?v=tr7OW2rVN4w (https://www.youtube.com/watch?v=tr7OW2rVN4w)
- https://www.youtube.com/watch?v=D2ohp-wEKXU (https://www.youtube.com/watch?v=D2ohp-wEKXU)
- Tutorial in our learning center: https://www.math2market.com/service-support/learning-center/digital-analysis-of-fibers-and-binder-content-of-four-carbon-paper-gdls.html (https://www.math2market.com/service-support/learning-center/digital-analysis-of-fibers-and-binder-content-of-four-carbon-paper-gdls.html)
Best regards,
Jonas
Dear Jonas,
Thank you very much for your detailed explanation and support.
I am impressed by how many different structural analyses can be performed in GeoDict. The visualization options and analysis capabilities are very helpful for my research.
In addition to importing catalyst layer structures from CT images, I am also interested in creating catalyst layer models directly within GeoDict.
Could you please advise me on how to incorporate actual catalyst data into GeoDict when generating a structure? For example, if I have information about the catalyst particles such as particle size distribution, shape, or loading, how can these data be implemented in GeoDict?
I would also like to know whether it is possible to connect individual particles together and represent them as a fiber-like structure within GeoDict. If so, which module or workflow would be most suitable for this purpose?
Thank you very much for your time and assistance.
Best regards,
Hello Shunsuke,
the structure generators FiberGeo and GrainGeo offer a large amount of possibilities to generate the desired structure.
Have a view at the different available object types in FiberGeo (https://geodict-userguide.math2market.de/2026/fibergeo_create_fiberoptions_crosssections.html) and GrainGeo (https://geodict-userguide.math2market.de/2026/graingeo_create_objectoptions_objecttypes.html).
There, you can define size distributions for each object type as described here (https://geodict-userguide.math2market.de/2026/graingeo_create_objectoptions_distribution.html).
There is no direct input for the loading in the structure generators. You can define a volume percentage, object number, density or grammage as described here (https://geodict-userguide.math2market.de/2026/graingeo_create_createoptions_stoppingcriterion.html).
There is a GeoApp called Bimodal Electrode (https://geodict-userguide.math2market.de/2026/geoapp_bimodalelectrode.html), where you can define a loading. However, it only generates a cathode or anode structure with spherical, elliptical or polyhedral particles and binder.
Regarding the connection of particles to a fiber shape, there are several possibilities:
1. If you don't need the individual particles resolved, you can simply generate fibers using FiberGeo.
2. In GrainGeo you have a particle type called sphere agglomerate (https://geodict-userguide.math2market.de/2026/graingeo_create_objectoptions_specific-parameters.html). If your particles have spherical shape, maybe this is a good object type for you?
3. You can first create a fiber structure with FiberGeo and then afterwards use GrainGeo with the option Create in Current (https://geodict-userguide.math2market.de/2026/graingeo_create_createoptions_in-current.html), and for the Center Distribution of the object choose On Current Objects (https://geodict-userguide.math2market.de/2026/graingeo_create_objectoptions_center-distribution.html). Then, the grains will only be placed where the fibers have been.
Best regards,
Janine
Thank you for your helpful response.
I have another question. I would like to use the material properties of a real carbon fiber in my GeoDict model. For example, I would like to define properties such as density, electrical conductivity, and other relevant material parameters.
Could you please explain how I can create or assign a custom material and input these properties in GeoDict?
Best regards,
Shunsuke Takai
Hello Shunsuke,
this is explained in the
Material Database User Guide (https://geodict-userguide.math2market.de/2026/materialdatabase_addingnewmaterialstothedatabase.html).
Additionally for GeoDict 2022 I created a
YouTube tutorial (https://www.youtube.com/watch?v=JoiRB7Z-c0o) (how to add a new material to the database starts at about 6:25) for this. Although there were some changes between GeoDict 2022 and 2026 the concept stays the same.
For a short summary what to do:
- Open the material database (Settings -> Open & Edit Material Database)
- Either enter a name for Add Material and click Add or choose a material already similar to your new custom material and click Copy.
- On the right find the parameters you want to change. Under the General tab decide if it is a solid material and which property groups you want to define.
- The density can then be entered under the Solid (or Fluid) tab, the electrical conductivity can be entered under the Electrical Conductivity tab
- After all parameters are set as needed click Save Database at the bottom of the dialog.
- Now you can choose this new material under the Constituent Materials tab in the solver options dialogs or in the Constituent Materials dialog.
Best regards,
Janine