Besides being a great pre- and post-processor for FEA, FEMAP is an exceptionally useful for working with medical imaging data. There’s native support for STL files and API extensions are readily used to extend functionality for constructing solid models. What we would like to emphasize in this article is how much more powerful FEMAP becomes when you use Meshlab before importing and converting it to a triangular mesh finite element model.
Typical STL files from medical imaging data sources are not sampled uniformly and more than likely contain extraneous vertexes, zero volume elements and have other issues. You could bring the STL file directly into FEMAP or use Meshlab to clean up the file before import. Meshlab additionally provides methods for repairing, smoothing and reconstructing data. It’s really simple to do, e.g., a Poisson-disk sampling and then a surface reconstruction to create a new mesh at a new level of mesh refinement.
This image was preprocessed with Meshlab. We used Poisson-disk sampling with Ball Pivoting Reconstruction sampled at just above the original image resolution. The triangle aspect ratio quality was greatly improved and all errors and redundancies in the model were removed. In many cases, this technique is so effective that a production ready FEA model can be built by importing an STL file directly into FEMAP as a set of three noded elements.