diff --git a/src/surface/sf_splines.scad b/src/surface/sf_splines.scad
new file mode 100644
index 00000000..e489bc79
--- /dev/null
+++ b/src/surface/sf_splines.scad
@@ -0,0 +1,90 @@
+function sf_splines(ctrl_pts, rspline, cspline) =
+    let(
+        leng_ctrl_pts = len(ctrl_pts),
+        cspl = is_undef(cspline) ? rspline : cspline,
+        r_pts = [
+		    for(r = 0; r < leng_ctrl_pts; r = r + 1)
+				rspline(ctrl_pts[r])
+		],
+        leng_r_pts0 = len(r_pts[0]),
+        leng_r_pts = len(r_pts)
+	)
+    [
+	    for(c = 0; c < leng_r_pts0; c = c + 1)
+            cspl([for(r = 0; r < leng_r_pts; r = r + 1) r_pts[r][c]]) 
+    ];
+
+/*
+use <bspline_curve.scad>;
+use <function_grapher.scad>;
+use <surface/sf_splines.scad>;
+
+ctrl_pts = [
+    [[0, 0, 20],  [60, 0, -35],   [90, 0, 60],    [200, 0, 5]],
+    [[0, 50, 30], [100, 60, -25], [120, 50, 120], [200, 50, 5]],
+    [[0, 100, 0], [60, 120, 35],  [90, 100, 60],  [200, 100, 45]],
+    [[0, 150, 0], [60, 150, -35], [90, 180, 60],  [200, 150, 45]]
+];
+
+thickness = 2;
+t_step = 0.05;
+degrees = 2;
+
+rspline = function(points) bspline_curve(t_step, degrees, points);
+cspline = function(points) bspline_curve(t_step, degrees, points);
+
+function_grapher(sf_splines(ctrl_pts, rspline, cspline), thickness);
+*/
+
+/*
+
+use <bezier_curve.scad>;
+use <function_grapher.scad>;
+use <surface/sf_splines.scad>;
+
+ctrl_pts = [
+    [[0, 0, 20],  [60, 0, -35],   [90, 0, 60],    [200, 0, 5]],
+    [[0, 50, 30], [100, 60, -25], [120, 50, 120], [200, 50, 5]],
+    [[0, 100, 0], [60, 120, 35],  [90, 100, 60],  [200, 100, 45]],
+    [[0, 150, 0], [60, 150, -35], [90, 180, 60],  [200, 150, 45]]
+];
+
+thickness = 2;
+t_step = 0.05;
+
+rspline = function(points) bezier_curve(t_step, points);
+cspline = function(points) bezier_curve(t_step, points);
+
+function_grapher(sf_splines(ctrl_pts, rspline, cspline), thickness);
+
+*/
+
+/*
+
+use <curve.scad>;
+use <function_grapher.scad>;
+use <surface/sf_splines.scad>;
+
+use <hull_polyline3d.scad>;
+
+ctrl_pts = [
+    [[0, 0, 20],  [20, 0, -15], [90, 0, 30], [200, 0, 5]],
+    [[0, 20, 30], [30, 30, -25], [80, 40, 20], [100, 50, 5]],
+    [[0, 100, 0], [20, 90, 15],  [90, 100, 10],  [100, 100, 45]],
+    [[0, 110, 0], [40, 120, -35], [90, 130, 20],  [120, 120, 15]]
+];
+
+thickness = 2;
+t_step = 0.05;
+
+rspline = function(points) curve(t_step, points);
+cspline = function(points) curve(t_step, points);
+
+function_grapher(sf_splines(ctrl_pts, rspline, cspline), thickness);
+
+for(i = [0:3]) {
+    %hull_polyline3d(ctrl_pts[i]);
+    #hull_polyline3d(curve(t_step, ctrl_pts[i]));
+}
+
+*/
\ No newline at end of file