irrlicht引擎中createOctTreeTriangleSelector()函数的参数意义有人解释一下吗?

Creates a simple ITriangleSelector, based on a mesh. Triangle selectors can be used for doing collision detection. Don't use this selector for a huge amount of triangles like in Quake3 maps.
[Visual Basic]
Public Function CreateOctTreeTriangleSelector( _
ByVal mesh As IMesh, _
ByVal node As ISceneNode, _
ByVal minimalPolysPerNode As Integer _
) As ITriangleSelector
[C#]
public ITriangleSelector CreateOctTreeTriangleSelector(
IMesh mesh,
ISceneNode node,
int minimalPolysPerNode
);