How to divide a 3D model into multiple cells

I am now working on finite element analysis.

I want to divide a 3D model into multiple cells and assign different physical property values to each cell.

Is there any such method?

When I created a STL file of a cylinder with multiple cells in AutoCAD and imported it with the importGeometry function of MATLAB, all the cells were merged.

Answer 1

[Selva Karna]

Segment unwanted voxels then covert stl.