diff --git a/Cargo.lock b/Cargo.lock
index 28fe388..801bfeb 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -731,12 +731,21 @@ dependencies = [
  "rayon",
 ]
 
+[[package]]
+name = "ray-tracing-material"
+version = "0.1.0"
+dependencies = [
+ "rand",
+ "ray-tracing-core",
+]
+
 [[package]]
 name = "ray-tracing-scene"
 version = "0.1.0"
 dependencies = [
  "rand",
  "ray-tracing-core",
+ "ray-tracing-material",
 ]
 
 [[package]]
diff --git a/Cargo.toml b/Cargo.toml
index 0c703a5..3b77f21 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,4 +1,4 @@
 [workspace]
 
-members = [ "ray-tracing-core", "ray-tracing-image", "ray-tracing-scene"]
+members = [ "ray-tracing-core", "ray-tracing-image", "ray-tracing-material", "ray-tracing-scene"]
 resolver = "2"
diff --git a/ray-tracing-core/src/aabb.rs b/ray-tracing-core/src/aabb.rs
index 603b290..ff2b41b 100644
--- a/ray-tracing-core/src/aabb.rs
+++ b/ray-tracing-core/src/aabb.rs
@@ -43,7 +43,7 @@ impl AABB {
             && pos.z <= self.max.z
     }
 
-    pub fn intersect_ray(self, ray: Ray) -> Option<Float> {
+    pub fn intersect_ray(self, ray: Ray, min: Float, max: Float) -> Option<Float> {
         todo!()
     }
 }
diff --git a/ray-tracing-core/src/lib.rs b/ray-tracing-core/src/lib.rs
index 4a51959..cd512f1 100644
--- a/ray-tracing-core/src/lib.rs
+++ b/ray-tracing-core/src/lib.rs
@@ -1,6 +1,7 @@
 pub mod aabb;
 pub mod camera;
 pub mod color;
+pub mod light;
 pub mod material;
 pub mod math;
 pub mod ray;
@@ -11,6 +12,7 @@ pub mod prelude {
     pub type Float = f32;
     pub use crate::aabb::AABB;
     pub use crate::color::Color;
+    pub use crate::light::Light;
     pub use crate::material::Material;
     pub use crate::math::*;
     pub use crate::ray::Ray;
diff --git a/ray-tracing-core/src/light.rs b/ray-tracing-core/src/light.rs
new file mode 100644
index 0000000..300ad7e
--- /dev/null
+++ b/ray-tracing-core/src/light.rs
@@ -0,0 +1,26 @@
+use crate::prelude::*;
+use rand::Rng;
+
+pub trait Light<R: Rng>: Sync {
+    fn emit(&self, w_in: Dir3, rng: &mut R) -> Color;
+}
+
+pub struct AreaLight {
+    pub(crate) color: Color,
+}
+
+impl AreaLight {
+    pub fn new(color: Color) -> Self {
+        Self { color }
+    }
+}
+
+impl<R: Rng> Light<R> for AreaLight {
+    fn emit(&self, w_in: Dir3, _rng: &mut R) -> Color {
+        if w_in.y() > 0.0 {
+            self.color
+        } else {
+            Color::black()
+        }
+    }
+}
diff --git a/ray-tracing-core/src/material.rs b/ray-tracing-core/src/material.rs
index ff22f87..cb55d74 100644
--- a/ray-tracing-core/src/material.rs
+++ b/ray-tracing-core/src/material.rs
@@ -3,52 +3,5 @@ use rand::Rng;
 
 /// All calculations for the material are done a tangent space of the intersection.
 pub trait Material<R: Rng>: Sync {
-    fn eval(&self, w_in: Dir3, w_out: Dir3, rng: &mut R) -> Option<Color> {
-        None
-    }
-
-    fn emit(&self, w_in: Dir3, rng: &mut R) -> Option<Color> {
-        None
-    }
-}
-
-pub struct DefaultMaterial {}
-
-impl<R: Rng> Material<R> for DefaultMaterial {
-    // evaluates the bsdf
-    fn eval(&self, _w_in: Dir3, _w_out: Dir3, _rng: &mut R) -> Option<Color> {
-        None
-    }
-}
-
-pub struct DiffuseMaterial {
-    color: Color,
-}
-
-impl DiffuseMaterial {
-    pub fn new(color: Color) -> Self {
-        Self { color }
-    }
-}
-
-impl<R: Rng> Material<R> for DiffuseMaterial {
-    fn eval(&self, _w_in: Dir3, _w_out: Dir3, _rng: &mut R) -> Option<Color> {
-        Some(self.color)
-    }
-}
-
-pub struct AreaLight {
-    color: Color,
-}
-
-impl AreaLight {
-    pub fn new(color: Color) -> Self {
-        Self { color }
-    }
-}
-
-impl<R: Rng> Material<R> for AreaLight {
-    fn emit(&self, _w_in: Dir3, _rng: &mut R) -> Option<Color> {
-        Some(self.color)
-    }
+    fn eval(&self, w_in: Dir3, w_out: Dir3, rng: &mut R) -> Color;
 }
diff --git a/ray-tracing-core/src/math/frame.rs b/ray-tracing-core/src/math/frame.rs
index 159eec4..c474165 100644
--- a/ray-tracing-core/src/math/frame.rs
+++ b/ray-tracing-core/src/math/frame.rs
@@ -39,7 +39,9 @@ mod test {
 
         dbg!(f);
 
-        dbg!(f.to_world(Dir3::new(0.0, 1.0, 0.0)));
+        let t = dbg!(f.to_world(Dir3::new(1.0, 1.0, 1.0)));
+
+        dbg!(f.to_frame(t));
 
         panic!()
     }
diff --git a/ray-tracing-core/src/renderer.rs b/ray-tracing-core/src/renderer.rs
index d128386..3ba7a73 100644
--- a/ray-tracing-core/src/renderer.rs
+++ b/ray-tracing-core/src/renderer.rs
@@ -50,27 +50,25 @@ where
         let mut count = 0;
 
         while let Some(i) = self.scene.intersect(r, 0.001, Float::INFINITY) {
-            if count > 4 {
-                break;
-            }
             let frame = i.tangent_frame();
             let w_in = frame.to_frame(-r.dir());
             let w_out = Dir3::generate_uniform_hemisphere(rng);
 
-            let mat = i.material();
-
-            if let Some(c) = mat.emit(w_in, rng) {
-                sum += alpha * c * w_out.y();
+            if let Some(light) = i.light() {
+                sum += alpha * light.emit(w_in, rng) * w_out.y();
             }
 
-            if let Some(c) = mat.eval(w_in, w_out, rng) {
-                alpha *= c;
+            if let Some(material) = i.material() {
+                alpha *= material.eval(w_in, w_out, rng) * w_out.y();
             } else {
                 return sum;
             }
 
             r = Ray::new(r.at(i.t()), frame.to_world(w_out), r.time());
             count += 1;
+            if count > 4 {
+                break;
+            }
         }
 
         sum
diff --git a/ray-tracing-core/src/scene.rs b/ray-tracing-core/src/scene.rs
index 524e2c9..8c07fb1 100644
--- a/ray-tracing-core/src/scene.rs
+++ b/ray-tracing-core/src/scene.rs
@@ -8,15 +8,22 @@ pub trait Scene<R: Rng> {
 pub struct Intersection<'sc, R: Rng> {
     t: Float,
     normal: Dir3,
-    material: &'sc dyn Material<R>,
+    material: Option<&'sc dyn Material<R>>,
+    light: Option<&'sc dyn Light<R>>,
 }
 
 impl<'sc, R: Rng> Intersection<'sc, R> {
-    pub fn new(t: Float, normal: Dir3, material: &'sc dyn Material<R>) -> Self {
+    pub fn new(
+        t: Float,
+        normal: Dir3,
+        material: Option<&'sc dyn Material<R>>,
+        light: Option<&'sc dyn Light<R>>,
+    ) -> Self {
         Self {
             t,
             normal,
             material,
+            light,
         }
     }
 
@@ -28,10 +35,14 @@ impl<'sc, R: Rng> Intersection<'sc, R> {
         self.normal
     }
 
-    pub fn material(&self) -> &'sc dyn Material<R> {
+    pub fn material(&self) -> Option<&'sc dyn Material<R>> {
         self.material
     }
 
+    pub fn light(&self) -> Option<&'sc dyn Light<R>> {
+        self.light
+    }
+
     pub fn tangent_frame(&self) -> Frame {
         Frame::from_normal(self.normal)
     }
diff --git a/ray-tracing-image/src/main.rs b/ray-tracing-image/src/main.rs
index 9bf2eff..da9515e 100644
--- a/ray-tracing-image/src/main.rs
+++ b/ray-tracing-image/src/main.rs
@@ -39,9 +39,9 @@ fn main() -> ImageResult<()> {
     let s = cornel();
 
     let c = BasicCamera::new(
-        640,
         400,
-        Pos3::new(-10.0, 0.0, 0.0),
+        400,
+        Pos3::new(-6.0, 0.0, 0.0),
         Dir3::new(1.0, 0.0, 0.0),
         Dir3::up(),
         Float::to_radians(90.0),
@@ -49,5 +49,5 @@ fn main() -> ImageResult<()> {
 
     let r = PathTracer::new(s, c);
 
-    render_image(r, "test.exr", 1024)
+    render_image(r, "test.exr", 1048)
 }
diff --git a/ray-tracing-material/Cargo.toml b/ray-tracing-material/Cargo.toml
new file mode 100644
index 0000000..0e4572f
--- /dev/null
+++ b/ray-tracing-material/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "ray-tracing-material"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+rand = "0.8.5"
+ray-tracing-core = { path = "../ray-tracing-core" }
diff --git a/ray-tracing-material/src/default.rs b/ray-tracing-material/src/default.rs
new file mode 100644
index 0000000..c8ae5a4
--- /dev/null
+++ b/ray-tracing-material/src/default.rs
@@ -0,0 +1,11 @@
+use rand::Rng;
+use ray_tracing_core::prelude::*;
+
+pub struct DefaultMaterial {}
+
+impl<R: Rng> Material<R> for DefaultMaterial {
+    // evaluates the bsdf
+    fn eval(&self, _w_in: Dir3, _w_out: Dir3, _rng: &mut R) -> Color {
+        Color::black()
+    }
+}
diff --git a/ray-tracing-material/src/diffuse.rs b/ray-tracing-material/src/diffuse.rs
new file mode 100644
index 0000000..9cdba40
--- /dev/null
+++ b/ray-tracing-material/src/diffuse.rs
@@ -0,0 +1,20 @@
+use rand::Rng;
+use ray_tracing_core::prelude::*;
+
+pub struct DiffuseMaterial {
+    pub(crate) albedo: Color,
+}
+
+impl DiffuseMaterial {
+    pub fn new(color: Color) -> Self {
+        Self {
+            albedo: color * FloatConsts::FRAC_1_PI,
+        }
+    }
+}
+
+impl<R: Rng> Material<R> for DiffuseMaterial {
+    fn eval(&self, _w_in: Dir3, _w_out: Dir3, _rng: &mut R) -> Color {
+        self.albedo
+    }
+}
diff --git a/ray-tracing-material/src/lib.rs b/ray-tracing-material/src/lib.rs
new file mode 100644
index 0000000..991b6b1
--- /dev/null
+++ b/ray-tracing-material/src/lib.rs
@@ -0,0 +1,2 @@
+pub mod default;
+pub mod diffuse;
diff --git a/ray-tracing-scene/Cargo.toml b/ray-tracing-scene/Cargo.toml
index 09f2662..ce8f09c 100644
--- a/ray-tracing-scene/Cargo.toml
+++ b/ray-tracing-scene/Cargo.toml
@@ -6,3 +6,4 @@ edition = "2021"
 [dependencies]
 rand = "0.8.5"
 ray-tracing-core = { path = "../ray-tracing-core" }
+ray-tracing-material = { path = "../ray-tracing-material" }
diff --git a/ray-tracing-scene/src/basic_scene.rs b/ray-tracing-scene/src/basic_scene.rs
index 7b315df..0e68498 100644
--- a/ray-tracing-scene/src/basic_scene.rs
+++ b/ray-tracing-scene/src/basic_scene.rs
@@ -1,7 +1,7 @@
 use rand::Rng;
-use ray_tracing_core::material::DefaultMaterial;
 use ray_tracing_core::prelude::*;
 use ray_tracing_core::scene::{Intersection, Scene};
+use ray_tracing_material::default::DefaultMaterial;
 
 pub struct BasicScene {
     pub(crate) spheres: Vec<(Pos3, Float)>,
@@ -30,7 +30,8 @@ impl<R: Rng> Scene<R> for BasicScene {
                 let int = Intersection::new(
                     d,
                     ((ray.start() + d * ray.dir()) - c).normalize(),
-                    &DefaultMaterial {},
+                    Some(&DefaultMaterial {}),
+                    None,
                 );
                 if d >= min && d <= max {
                     if let Some(i) = intersection.as_ref() {
diff --git a/ray-tracing-scene/src/lib.rs b/ray-tracing-scene/src/lib.rs
index db5f491..d56f56c 100644
--- a/ray-tracing-scene/src/lib.rs
+++ b/ray-tracing-scene/src/lib.rs
@@ -1,7 +1,2 @@
-use rand::Rng;
-use ray_tracing_core::material::DefaultMaterial;
-use ray_tracing_core::prelude::*;
-
 pub mod basic_scene;
-
 pub mod triangle_bvh;
diff --git a/ray-tracing-scene/src/triangle_bvh.rs b/ray-tracing-scene/src/triangle_bvh.rs
index a5fae51..b6a3409 100644
--- a/ray-tracing-scene/src/triangle_bvh.rs
+++ b/ray-tracing-scene/src/triangle_bvh.rs
@@ -9,10 +9,15 @@ type Index = u32;
 pub struct TriangleBVH<R: Rng> {
     vertices: Vec<Pos3>,
     triangles: Vec<Triangle>,
-    materials: Vec<Box<dyn Material<R>>>,
+    materials: Vec<BVHMaterial<R>>,
     bvh: Vec<Node>,
 }
 
+struct BVHMaterial<R: Rng> {
+    material: Option<Box<dyn Material<R>>>,
+    light: Option<Box<dyn Light<R>>>,
+}
+
 #[derive(Debug, Clone, Copy)]
 enum Node {
     Inner {
@@ -53,7 +58,7 @@ fn triangle_intersection(ray: Ray, v: [Pos3; 3]) -> Option<Float> {
     let inv_det = 1.0 / det;
     let s = ray.start() - v[0];
     let u = inv_det * s.dot(ray_cross_e2);
-    if u < 0.0 || u > 1.0 {
+    if !(0.0..=1.0).contains(&u) {
         return None;
     }
 
@@ -82,11 +87,7 @@ fn triangle_normal(v: [Pos3; 3]) -> Dir3 {
 }
 
 impl<R: Rng> TriangleBVH<R> {
-    fn new(
-        vertices: Vec<Pos3>,
-        triangles: Vec<Triangle>,
-        materials: Vec<Box<dyn Material<R>>>,
-    ) -> Self {
+    fn new(vertices: Vec<Pos3>, triangles: Vec<Triangle>, materials: Vec<BVHMaterial<R>>) -> Self {
         Self {
             vertices,
             bvh: vec![Node::Leaf {
@@ -120,7 +121,40 @@ impl<R: Rng> TriangleBVH<R> {
                 left_aabb,
                 right,
                 right_aabb,
-            } => todo!(),
+            } => {
+                let left_intersect = left_aabb.intersect_ray(ray, min, max);
+                let right_intersect = right_aabb.intersect_ray(ray, min, max);
+
+                match (left_intersect, right_intersect) {
+                    (None, None) => None,
+                    (None, Some(_)) => self.intersect_bvh(right, ray, min, max),
+                    (Some(_), None) => self.intersect_bvh(left, ray, min, max),
+                    (Some(l), Some(r)) => {
+                        let close;
+                        let far;
+                        if l < r {
+                            close = left;
+                            far = right;
+                        } else {
+                            close = right;
+                            far = left;
+                        }
+
+                        if let Some(close_intersect) = self.intersect_bvh(close, ray, min, max) {
+                            if let Some(far_intersect) = self
+                                .intersect_bvh(far, ray, min, Float::min(min, close_intersect.1))
+                                .filter(|far_intersect| far_intersect.1 < close_intersect.1)
+                            {
+                                Some(far_intersect)
+                            } else {
+                                Some(close_intersect)
+                            }
+                        } else {
+                            self.intersect_bvh(far, ray, min, max)
+                        }
+                    }
+                }
+            }
             Node::Leaf { start, count } => {
                 let mut intersection = None;
                 for i in start..(start + count) {
@@ -148,19 +182,24 @@ impl<R: Rng> Scene<R> for TriangleBVH<R> {
         let (i, t) = self.intersect_bvh(0, ray, min, max)?;
 
         let triangle = self.triangles[i as usize];
-        let material = self.materials[triangle.material as usize].as_ref();
+        let material = &self.materials[triangle.material as usize];
 
         let n = triangle_normal(self.get_vertices(i)).normalize();
 
-        Some(Intersection::new(t, n, material))
+        Some(Intersection::new(
+            t,
+            n,
+            material.material.as_deref(),
+            material.light.as_deref(),
+        ))
     }
 }
 
 pub mod examples {
-    use super::{Triangle, TriangleBVH};
+    use super::{BVHMaterial, Triangle, TriangleBVH};
     use rand::Rng;
-    use ray_tracing_core::material::{AreaLight, DiffuseMaterial};
-    use ray_tracing_core::prelude::*;
+    use ray_tracing_core::{light::AreaLight, prelude::*};
+    use ray_tracing_material::diffuse::DiffuseMaterial;
 
     pub fn cornel<R: Rng>() -> TriangleBVH<R> {
         let side_length = 1.5;
@@ -196,10 +235,22 @@ pub mod examples {
                 Triangle::new([11, 9, 10], 3),
             ],
             vec![
-                Box::new(DiffuseMaterial::new(Color::new(0.8, 0.8, 0.8))),
-                Box::new(DiffuseMaterial::new(Color::new(0.9, 0.0, 0.0))),
-                Box::new(DiffuseMaterial::new(Color::new(0.0, 0.9, 0.0))),
-                Box::new(AreaLight::new(Color::new(5.0, 5.0, 5.0))),
+                BVHMaterial {
+                    material: Some(Box::new(DiffuseMaterial::new(Color::new(0.8, 0.8, 0.8)))),
+                    light: None,
+                },
+                BVHMaterial {
+                    material: Some(Box::new(DiffuseMaterial::new(Color::new(0.9, 0.0, 0.0)))),
+                    light: None,
+                },
+                BVHMaterial {
+                    material: Some(Box::new(DiffuseMaterial::new(Color::new(0.0, 0.9, 0.0)))),
+                    light: None,
+                },
+                BVHMaterial {
+                    material: None,
+                    light: Some(Box::new(AreaLight::new(Color::white() * 30.0))),
+                },
             ],
         )
     }