diff --git a/src/surface/sf_hull.scad b/src/surface/sf_hull.scad
new file mode 100644
index 00000000..e46839fe
--- /dev/null
+++ b/src/surface/sf_hull.scad
@@ -0,0 +1,49 @@
+module sf_hull(points, thickness) {
+    rows = len(points);
+    columns = len(points[0]);
+
+    yi_range = [0:rows - 2];
+    xi_range =  [0:columns - 2];
+
+    half_thickness = thickness / 2;
+
+    module hull_pts(tri) {
+       hull() {
+           translate(tri[0]) sphere(half_thickness);
+           translate(tri[1]) sphere(half_thickness);
+           translate(tri[2]) sphere(half_thickness);
+       }    
+    }
+    
+    module tri_to_hull_faces(tri1, tri2) {
+       hull_pts(tri1);
+       hull_pts(tri2);
+    }    
+    
+    twintri_lt = 
+        [
+            for(yi = yi_range)
+                for(xi = xi_range)
+                    [
+                        [
+                            points[yi][xi], 
+                            points[yi][xi + 1], 
+                            points[yi + 1][xi]
+                        ],
+                        [
+                            points[yi + 1][xi], 
+                            points[yi][xi + 1], 
+                            points[yi + 1][xi + 1]                        
+                        ]
+                    ]
+        ];
+
+    for(twintri = twintri_lt) {
+        tri_to_hull_faces(twintri[0], twintri[1]);
+    }  
+}
+
+// override it to test
+module test_function_grapher_faces(points, faces) {
+
+}
\ No newline at end of file