Efficient usage: 1D (line) elements, 2D quadrilateral elements, 3D hexahedral elements;
Required number of points (Ngp) for a polynomial of degree d:
1D:
Ngp= (d+1)/2
2D:
Ngp(2D)=(Ngp(1D))2
3D:
Ngp(3D)=(Ngp(1D))3