Re-Meshing part of a layered domain to include several geological features

Hello everyone, I'm writing to ask for your help in solving a modeling problem. I'm working on a single layer domain in which I want to include variable-shaped and sized 3d polygons inside  by remeshing the elements in an unstructured mesh based on tetrahedra. When I try to remesh with tetgen using the files in format: GO CAD ASCII I get the error message from tetgen: A self intersection was detected, no matter what solid I try to import. Also I can visualize the 3d solids in the layer (see in attachment) My questions are:  * what is the best format of the 3d files to work with? * Did you experience something similar?  * How can I resolve?  thank you in advance Antonio  

Hi Antonio, The problem is not the format. if you can display the file in FEFLOW, then it can be understood by the mesh generator. The problem is that the GOCAD surface intersects with the border faces of your 1 layer model. The repair operation is only available via the 3D Supermesh workflow. In practical terms, you would need to reduce the volume in GOCAD and then try to mesh it again in FEFLOW. Best, Carlos

Dear Carlos and everyone, I haven't found a solution yet. The clay deposits I would like to incorporate into the model are contained in a MOVE project (Petroleum expert software), and from this project, I can download ASCII files which are .dat files (point files with X, Y, and Z coordinates). After downloading them, I open them in ArcGIS and create shapefiles, which I then import into Feflow. At that point, I perform remeshing of the selection of the elements of interest, but the result is that I have tetrahedra scattered between the two slices and not confined between the top and bottom surfaces of the clay bodies so that it's impossible to select only the tetrahedra I need. Here is a screenshot of the situation: the yellow dots represent the base and roof surfaces of the clay deposits. Is the procedure correct, or am I doing something wrong? And how can I quickly select only the tetrahedra I need? Thank you in advance for your kind response