This Demonstration shows spline-averaged points of a Gosper curve displayed as a spline surface. With all sliders on the left, you can see the original 2D Gosper curve. The height slider adds values to the points of the curve. The height period slider determines a periodic height. The linear sequence of points of the averaged Gosper curve are partitioned in blocks of size determined by the averaging size slider. The resulting rectangular array of 3D points are interpreted as the control points of a NURBS surface and this surface is displayed.