Reply To: Something about settlingCube3D
the objects for such particle simulations are described my SmoothIndicators, e.g. https://www.openlb.net/DoxyGen/html/db/d8b/classolb_1_1SmoothIndicatorCylinder3D.html
You will have to create a new one, which calculates the physical parameters (or you hardcode them if you know them) in the constructor. Also the ()-operator is used to decide wheater a given point is within the particle or outside. at this point you have to include the STL. You can probably take advantage of the included STL-reader : https://www.openlb.net/DoxyGen/html/d2/d60/classolb_1_1STLreader.html
I suggest you use an existing SmoothIndicator as a blueprint and have a look at the STLreader (it is applied e.g. in the cylinder3D example case.