diff --git a/src/raytracer.ml b/src/raytracer.ml
index 582d6903..739d9488 100644
--- a/src/raytracer.ml
+++ b/src/raytracer.ml
@@ -15,6 +15,19 @@ type hit_rec = { t : float;
 
 type hit = hit_rec option
 
+let random_in_unit_sphere () =
+  let p = ref (Vec3.of_floats ((Random.float 1.0),
+                               (Random.float 1.0),
+                               (Random.float 1.0))) in
+  while ((Vec3.dot !p !p) >= 1.0) do
+    p := Vec3.mul 2.0 (Vec3.sub (Vec3.of_floats ((Random.float 1.0),
+                                                 (Random.float 1.0),
+                                                 (Random.float 1.0)))
+                         (Vec3.of_floats (1., 1., 1.)))
+  done;
+  !p
+;;
+
 
 let hit_sphere sphere ray (tmin, tmax) =
   let oc = sub ray.origin sphere.center in
@@ -63,16 +76,13 @@ and hit h ray (tmin, tmax) =
   | World w -> hit_world w ray (tmin, tmax)
 
 
-let get_color world ray =
+let rec get_color world ray =
   match (hit world ray (0., Float.infinity)) with
   Some hit_result ->
-    let t = hit_result.t in
-    if (t > 0.0)
-    then let n = hit_result.normal in
-      mul 0.5 (Vec3.of_floats (n.x +. 1., n.y +. 1., n.z +. 1.))
-    else let unit_direction = unit_vector ray.dir in
-      let t = 0.5 *. (unit_direction.y +. 1.0) in
-      add (mul (1.0 -. t) {x= 1.0; y=1.0; z= 1.0}) (mul t {x= 0.5; y= 0.7; z= 1.0})
+    let target = Vec3.add (Vec3.add hit_result.p hit_result.normal) 
+        (random_in_unit_sphere ()) in
+    Vec3.mul 0.5 (get_color world {origin = hit_result.p;
+                                   dir = Vec3.sub target hit_result.p})
   | None ->
     let unit_direction = unit_vector ray.dir in
     let t = 0.5 *. (unit_direction.y +. 1.0) in