public SketchModel()
	{
		s = new ArrayList<DelaunayTriangle>();
		j = new ArrayList<DelaunayTriangle>();
		t = new ArrayList<DelaunayTriangle>();
		triangles = new ArrayList<DelaunayTriangle>();
		prunedTriangles = new ArrayList<DelaunayTriangle>();
		subdividedTriangles = new ArrayList<DelaunayTriangle>();
		considered = new ArrayList<DelaunayTriangle>();
	}