diff --git a/rust-toolchain.toml b/rust-toolchain.toml
index e89a613..c0c3cf9 100644
--- a/rust-toolchain.toml
+++ b/rust-toolchain.toml
@@ -1,3 +1,3 @@
 [toolchain]
 channel = "1.77.0"
-components = [ "rustfmt", "clippy" ]
+components = [ "rustfmt", "clippy", "rust-analyzer", "rust-src" ]
diff --git a/src/camera.rs b/src/camera.rs
index c60309f..63a9f78 100644
--- a/src/camera.rs
+++ b/src/camera.rs
@@ -74,7 +74,6 @@ mod tests {
     use super::*;
 
     use crate::color::Color;
-    use crate::matrix;
     use crate::vector;
     use approx::relative_eq;
     use core::f64::consts::PI;
@@ -97,10 +96,10 @@ mod tests {
     #[test]
     fn test_camera_pixel_size_calculation() {
         let camera = Camera::new(200, 125, FRAC_PI_2);
-        relative_eq!(camera.pixel_size(), 0.01, epsilon = matrix::EPSILON);
+        relative_eq!(camera.pixel_size(), 0.01, epsilon = crate::EPSILON);
 
         let camera = Camera::new(125, 200, FRAC_PI_2);
-        relative_eq!(camera.pixel_size(), 0.01, epsilon = matrix::EPSILON);
+        relative_eq!(camera.pixel_size(), 0.01, epsilon = crate::EPSILON);
     }
 
     #[test]
diff --git a/src/color.rs b/src/color.rs
index f7459be..033974e 100644
--- a/src/color.rs
+++ b/src/color.rs
@@ -13,7 +13,6 @@ impl Color {
     }
 }
 
-pub const EPSILON: f64 = 0.001;
 pub const WHITE: Color = Color {
     red: 1.0,
     green: 1.0,
@@ -22,9 +21,9 @@ pub const WHITE: Color = Color {
 
 impl PartialEq for Color {
     fn eq(&self, other: &Self) -> bool {
-        let red_diff = (self.red - other.red).abs() <= EPSILON;
-        let green_diff = (self.green - other.green).abs() <= EPSILON;
-        let blue_diff = (self.blue - other.blue).abs() <= EPSILON;
+        let red_diff = (self.red - other.red).abs() <= crate::EPSILON;
+        let green_diff = (self.green - other.green).abs() <= crate::EPSILON;
+        let blue_diff = (self.blue - other.blue).abs() <= crate::EPSILON;
 
         red_diff && green_diff && blue_diff
     }
diff --git a/src/lib.rs b/src/lib.rs
index 995d511..f223a96 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,6 +1,8 @@
 #[macro_use]
 extern crate impl_ops;
 
+pub const EPSILON: f64 = 0.001;
+
 pub mod camera;
 pub mod canvas;
 pub mod color;
diff --git a/src/main.rs b/src/main.rs
index a645ec0..d7e0f45 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -81,7 +81,7 @@ fn main() {
     world.objects.push(right);
     world.objects.push(left);
 
-    let mut camera = camera::Camera::new(500, 250, FRAC_PI_3);
+    let mut camera = camera::Camera::new(400, 400, FRAC_PI_3);
     camera.transform =
         matrix::view_transform(point!(0, 1.5, -5), point!(0, 1, 0), vector!(0, 1, 0));
 
diff --git a/src/matrix.rs b/src/matrix.rs
index 09be60e..1e7ab57 100644
--- a/src/matrix.rs
+++ b/src/matrix.rs
@@ -180,8 +180,6 @@ pub fn view_transform(from: Tuple, to: Tuple, up: Tuple) -> Matrix {
     orientation * Matrix::identity(4).translation(-from.x, -from.y, -from.z)
 }
 
-pub const EPSILON: f64 = 0.001;
-
 impl PartialEq for Matrix {
     fn eq(&self, other: &Self) -> bool {
         if self.matrix.is_empty() && other.matrix.is_empty() {
@@ -196,7 +194,7 @@ impl PartialEq for Matrix {
 
             for x in 0..lines {
                 for y in 0..columns {
-                    if (self.at(x, y) - other.at(x, y)).abs() > EPSILON {
+                    if (self.at(x, y) - other.at(x, y)).abs() > crate::EPSILON {
                         return false;
                     }
                 }
diff --git a/src/ray.rs b/src/ray.rs
index 0f7b10f..7243bab 100644
--- a/src/ray.rs
+++ b/src/ray.rs
@@ -107,6 +107,7 @@ impl Intersection<'_> {
             t: self.t,
             object: self.object,
             point,
+            over_point: point + normalv * crate::EPSILON,
             eyev,
             normalv,
             inside,
@@ -127,6 +128,7 @@ pub struct Computation<'a> {
     pub t: f64,
     pub object: &'a Sphere,
     pub point: Tuple,
+    pub over_point: Tuple,
     pub eyev: Tuple,
     pub normalv: Tuple,
     pub inside: bool,
@@ -287,6 +289,26 @@ mod tests {
         assert_eq!(intersect.object, &sphere);
     }
 
+    #[test]
+    fn test_hit_offset_point() {
+        let charles = Ray {
+            origin: point!(0.0, 0.0, -5.0),
+            direction: vector!(0.0, 0.0, 1.0),
+        };
+
+        let mut sphere = Sphere::init();
+        sphere.transform = Matrix::identity(4).translation(0.0, 0.0, 1.0);
+
+        let i = Intersection {
+            t: 5.0,
+            object: &sphere,
+        };
+        let comps = i.prepare_computations(&charles);
+
+        assert!(comps.over_point.z < -crate::EPSILON / 2.0);
+        assert!(comps.point.z > comps.over_point.z);
+    }
+
     #[test]
     fn test_hit() {
         let i1 = Intersection {
diff --git a/src/tuple.rs b/src/tuple.rs
index 5de96e5..6d8f81c 100644
--- a/src/tuple.rs
+++ b/src/tuple.rs
@@ -1,5 +1,5 @@
-use crate::matrix;
 use crate::matrix::*;
+use crate::{matrix, EPSILON};
 use std::ops;
 
 #[derive(Debug, Clone, Copy)]
@@ -120,8 +120,6 @@ impl Tuple {
     }
 }
 
-pub const EPSILON: f64 = 0.001;
-
 impl PartialEq for Tuple {
     fn eq(&self, other: &Self) -> bool {
         let x_diff = (self.x - other.x).abs() <= EPSILON;
diff --git a/src/world.rs b/src/world.rs
index 0b82ec9..1a7df3a 100644
--- a/src/world.rs
+++ b/src/world.rs
@@ -75,7 +75,7 @@ impl World {
                 comps.point,
                 comps.eyev,
                 comps.normalv,
-                false,
+                self.is_shadowed(&comps.over_point),
             );
             current_color = current_color + color;
         }
diff --git a/tests/scenarios.rs b/tests/scenarios.rs
new file mode 100644
index 0000000..e007275
--- /dev/null
+++ b/tests/scenarios.rs
@@ -0,0 +1,32 @@
+use raytracer::{
+    color::Color,
+    light::Light,
+    matrix::Matrix,
+    point,
+    ray::{Intersection, Ray, Sphere},
+    tuple::Tuple,
+    vector,
+    world::World,
+};
+
+#[test]
+// test shadowed scene
+fn shade_git_given_an_intersection_in_shadow() {
+    let mut w = World::new();
+    w.lights.push(Light {
+        position: point!(0, 0, -10),
+        intensity: Color::new(1.0, 1.0, 1.0),
+    });
+    w.objects.push(Sphere::init());
+    let mut s2 = Sphere::init();
+    s2.transform = Matrix::identity(4).translation(0.0, 0.0, 10.0);
+    w.objects.push(s2);
+    let r = Ray::new(point!(0, 0, 5), vector!(0, 0, 1));
+    let i = Intersection {
+        t: 4.0,
+        object: &w.objects[1],
+    };
+    let comps = i.prepare_computations(&r);
+    let c = w.shade_hit(&comps);
+    assert_eq!(c, Color::new(0.1, 0.1, 0.1));
+}