The Finite Elements object allows the definition of three-dimensional objects in Modalys, using a mesh, which is then converted to modal data with the help of numerical methods.
Although the instantiation of the 'finite-element object itself is documented within the Object Reference, this section of the documentation will eventually be expanded to include the family of functions that assist in the creation of these objects.
For the moment, until the forthcoming update of the Modalys documentation, we suggest you take a look at the Finite Elements .pdf documentation from 2003, along with the various examples which are included in the Modalys distribution.