CFD Online Discussion Forums - using toposet for creating porous zone

i am trying to create porous zone using toposet.Already one of the tutorials is porousblockage in tuturials of pisfoam.now i am trying to create the porous block which is square block using stl file instead of using boxToCell

shown blow boxToCell

// porousBlockage
{
name porousBlockageCellSet;
type cellSet;
action new;
source boxToCell;
sourceInfo
{
box (-0.5 -0.5 -0.1) (0.5 0.5 0.1);
}

how to modify it to be surfaceToCell by using stl file as source,but i do not understand what is meant by outsidepoints,include Cut ,.......

can any one help ?

{
name porousBlockageCellSet;
type cellSet;
action new;
source surfaceToCell;
sourceInfo
{
file "centerblock1.stl";
//outsidePoints ((-0.5 -0.5 0));
// includeCut false;
//includeInside true;
// includeOutside false;
nearDistance 1e5;
// curvature -100;
}