If true than all the GeometryModels have both Material and BackMaterial set. This means that all the TriangleIndices can be visible from both sides.

public bool ForceTwoSidedMaterials { get; set; }

Public Property ForceTwoSidedMaterials As Boolean

public:
property bool ForceTwoSidedMaterials {
	bool get ();
	void set (bool value);
}