diff --git a/src/primitive.rs b/src/primitive.rs
index b677a0a..9ef2bc9 100644
--- a/src/primitive.rs
+++ b/src/primitive.rs
@@ -104,7 +104,7 @@ impl BoundingBox {
     }
 }
 // PRIMITIVE TRAIT -----------------------------------------------------------------
-pub trait Primitive {
+pub trait Primitive: Send + Sync {
     fn intersect_ray(&self, ray: &Ray) -> Option<Intersection>;
     fn intersect_bounding_box(&self, ray: &Ray) -> Option<Point3<f32>>;
     fn get_material(&self) -> Arc<Material>;
@@ -495,7 +495,7 @@ impl Primitive for Rectangle {
 }
 
 // BOX -----------------------------------------------------------------
-pub struct Box {
+pub struct Cube {
     width: f32,
     height: f32,
     depth: f32,
@@ -503,11 +503,11 @@ pub struct Box {
     bounding_box: BoundingBox,
 }
 
-impl Box {
+impl Cube {
     fn new(width: f32, height: f32, depth: f32, material: Arc<Material>) -> Self {
         let trf = Point3::new(width / 2.0, height / 2.0, depth / 2.0);
         let bln = Point3::new(-width / 2.0, -height / 2.0, -depth / 2.0);
-        Box {
+        Cube {
             width,
             height,
             depth,
@@ -516,11 +516,11 @@ impl Box {
         }
     }
     pub fn unit(material: Arc<Material>) -> Self {
-        Box::new(2.0, 2.0, 2.0, material)
+        Cube::new(2.0, 2.0, 2.0, material)
     }
 }
 
-impl Primitive for Box {
+impl Primitive for Cube {
     fn intersect_ray(&self, ray: &Ray) -> Option<Intersection> {
         // Compute the minimum and maximum t-values for each axis of the bounding box
         let t1 = (self.bounding_box.bln - ray.a).component_div(&ray.b);
diff --git a/src/scene.rs b/src/scene.rs
index bb2e784..3195be2 100644
--- a/src/scene.rs
+++ b/src/scene.rs
@@ -5,35 +5,25 @@ use nalgebra::Vector3;
 use std::sync::Arc;
 
 pub struct Scene {
-    pub primitives: Vec<Arc<dyn Primitive>>,
-    pub lights: Vec<Arc<Light>>,
-    pub cameras: Vec<Arc<Camera>>,
+    pub primitives: Arc<Vec<Box<dyn Primitive>>>,
+    pub lights: Arc<Vec<Light>>,
+    pub cameras: Arc<Vec<Camera>>,
     pub ambient_light: Arc<Vector3<f32>>,
 }
 
 impl Scene {
-    // Creates a new Scene with given parameters
+    // Creates a scene
     pub fn new(
-        primitives: Vec<Arc<dyn Primitive>>,
-        lights: Vec<Arc<Light>>,
-        cameras: Vec<Arc<Camera>>,
-        ambient_light: Arc<Vector3<f32>>,
+        primitives: Vec<Box<dyn Primitive>>,
+        lights: Vec<Light>,
+        cameras: Vec<Camera>,
+        ambient_light: Vector3<f32>,
     ) -> Self {
         Scene {
-            primitives,
-            lights,
-            cameras,
-            ambient_light,
-        }
-    }
-
-    // Creates an empty Scene with default values
-    pub fn empty() -> Self {
-        Scene {
-            primitives: Vec::new(),
-            lights: Vec::new(),
-            cameras: Vec::new(),
-            ambient_light: Arc::new(Vector3::new(0.0, 0.0, 0.0)),
+            primitives: Arc::new(primitives),
+            lights: Arc::new(lights),
+            cameras: Arc::new(cameras),
+            ambient_light: Arc::new(ambient_light),
         }
     }
 }