Hi Ahmed, thats classic reverse engineering. If thats a theoretical, calculated mesh or a scan doesn't matter to the software, as long as you can save a STL from it. The good part is, that the digitally created file is perfect (should be), so you do not have to bother about holes. Topology optimized usually is very organic. So using a classic approach to fit single surfaces such as planes and cylinders is not suitable. Thats why most people then use the automated approach. That usually fits a set of quads over the model that get converted to NURBS, or smarter. There is plenty of software available. nTopology does it themselves, as well as Spaceclaim. There is cheaper Rhino based solutions. Or just use a service provider.

Thank you Gerd Schwaderer for the detailed answer.

Actually, I can not save my results as an STL file! The reason is that I am not using any software. I am developing my own algorithm, using python, and I have only the matrix and the picture of the optimum design.

The matrix (mAcro-matrix, see the first image) contains integers. Each integer indicates a specific matrix (mIcro-matrix, see the second image). Each micro-matrix contains a fraction that indicates the optimum pseudo density value.

I need to convert this group of numbers to an STL file.

Thank you..

Well, if those numbers are coordinate triples, that would certainly give you an ascii format STl file.

The numbers are just indicators for the shape and density but I could extract the coordinates from the numbers at the top and left margins. Then I will try to get the STEP file from that ASCII.

I found this code "Top3dSTL_v3.m" at:

Article An efficient 3D topology optimization code written in Matlab

I believe it will help anyone interested..

You might be interested in the free education edition of PERMAS.

See https://www.intes.de/edu

Check out the Design Wizard in VisPER. You can easily generate .stl files from the result of your topology optimization.