refactor: scene deserialization organisation

src/objects/cube.rs

@@ -11,7 +11,6 @@ use super::hit::Hit;
 #[derive(Debug)]
 pub struct Cube {
     faces: Vec<Arc<dyn Hittable>>,
-    material: Arc<dyn Material>,
 }
 
 impl Cube {
@@ -34,7 +33,7 @@ impl Cube {
             Arc::new(Quad::new(p5, p6, p7, p8, material.clone())),
             Arc::new(Quad::new(p4, p3, p7, p8, material.clone())),
         ];
-        Self { faces, material }
+        Self { faces }
     }
 }