diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4a62839..48a0af5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -54,6 +54,9 @@ if("${CMAKE_CURRENT_LIST_DIR}/primitive/objmodel.cpp" IN_LIST primitive_src)
     add_definitions(-DOBJMODEL_FOUND)
 endif()
 
+add_executable(tracey_ex4 ex4.cpp)
+target_link_libraries(tracey_ex4 tracey)
+
 
 
 
diff --git a/common/brdfread.cpp b/common/brdfread.cpp
new file mode 100644
index 0000000..3032998
--- /dev/null
+++ b/common/brdfread.cpp
@@ -0,0 +1,202 @@
+// Copyright 2005 Mitsubishi Electric Research Laboratories All Rights Reserved.
+
+// Permission to use, copy and modify this software and its documentation without
+// fee for educational, research and non-profit purposes, is hereby granted, provided
+// that the above copyright notice and the following three paragraphs appear in all copies.
+
+// To request permission to incorporate this software into commercial products contact:
+// Vice President of Marketing and Business Development;
+// Mitsubishi Electric Research Laboratories (MERL), 201 Broadway, Cambridge, MA 02139 or
+// <license@merl.com>.
+
+// IN NO EVENT SHALL MERL BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL,
+// OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND
+// ITS DOCUMENTATION, EVEN IF MERL HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
+
+// MERL SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED
+// HEREUNDER IS ON AN "AS IS" BASIS, AND MERL HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT,
+// UPDATES, ENHANCEMENTS OR MODIFICATIONS.
+#include "common/brdfread.h"
+
+BRDFRead::BRDFRead(const char *filename) {
+  if (!readBrdf(filename)) {
+    std::cerr << "Cannot read BRDF file: " << filename << std::endl;
+    exit(0);
+  }
+}
+
+Color BRDFRead::lookupBrdfValues(double theta_in, double phi_in, double theta_out, double phi_out) {
+  // std::cerr << theta_in << "," << theta_out;
+  // Convert to halfangle / difference angle coordinates
+  double theta_half, phi_half, theta_diff, phi_diff;
+  std_coords_to_half_diff_coords(theta_in, phi_in, theta_out, phi_out, theta_half, phi_half, theta_diff, phi_diff);
+
+  // Find index.
+  // Note that phi_half is ignored, since isotropic BRDFs are assumed
+  int ind = phi_diff_index(phi_diff) + theta_diff_index(theta_diff) * BRDF_SAMPLING_RES_PHI_D / 2 +
+            theta_half_index(theta_half) * BRDF_SAMPLING_RES_PHI_D / 2 * BRDF_SAMPLING_RES_THETA_D;
+
+  Color color;
+  color.r = static_cast<float>(brdfData[ind] * RED_SCALE);
+  color.g = static_cast<float>(
+      brdfData[ind + BRDF_SAMPLING_RES_THETA_H * BRDF_SAMPLING_RES_THETA_D * BRDF_SAMPLING_RES_PHI_D / 2] *
+      GREEN_SCALE);
+  color.b = static_cast<float>(
+      brdfData[ind + BRDF_SAMPLING_RES_THETA_H * BRDF_SAMPLING_RES_THETA_D * BRDF_SAMPLING_RES_PHI_D] * BLUE_SCALE);
+
+  // std::cerr << red_val << "," <<green_val << "," << blue_val<< std::endl;
+  if (color.r < 0.0 || color.g < 0.0 || color.b < 0.0)
+    fprintf(stderr, "Below horizon.\n");
+  return color;
+}
+
+bool BRDFRead::readBrdf(const char *filename) {
+  FILE *f = fopen(filename, "rb");
+  if (!f)
+    return false;
+
+  int dims[3];
+  size_t numbytes = fread(dims, sizeof(int), 3, f);
+  if (numbytes == 0) {
+    return false;
+  }
+  int n = dims[0] * dims[1] * dims[2];
+  if (n != BRDF_SAMPLING_RES_THETA_H * BRDF_SAMPLING_RES_THETA_D * BRDF_SAMPLING_RES_PHI_D / 2) {
+    fprintf(stderr, "Dimensions don't match\n");
+    fclose(f);
+    return false;
+  }
+
+  brdfData = (double *)malloc(sizeof(double) * 3 * n);
+  numbytes = fread(brdfData, sizeof(double), 3 * n, f);
+  if (numbytes == 0) {
+    return false;
+  }
+
+  fclose(f);
+  return true;
+}
+
+void BRDFRead::cross_product(double *v1, double *v2, double *out) {
+  out[0] = v1[1] * v2[2] - v1[2] * v2[1];
+  out[1] = v1[2] * v2[0] - v1[0] * v2[2];
+  out[2] = v1[0] * v2[1] - v1[1] * v2[0];
+}
+
+void BRDFRead::normalize(double *v) {
+  // normalize
+  double len = sqrt(v[0] * v[0] + v[1] * v[1] + v[2] * v[2]);
+  v[0] = v[0] / len;
+  v[1] = v[1] / len;
+  v[2] = v[2] / len;
+}
+
+void BRDFRead::rotate_vector(double *vector, double *axis, double angle, double *out) {
+  double temp;
+  double cross[3];
+  double cos_ang = cos(angle);
+  double sin_ang = sin(angle);
+
+  out[0] = vector[0] * cos_ang;
+  out[1] = vector[1] * cos_ang;
+  out[2] = vector[2] * cos_ang;
+
+  temp = axis[0] * vector[0] + axis[1] * vector[1] + axis[2] * vector[2];
+  temp = temp * (1.0 - cos_ang);
+
+  out[0] += axis[0] * temp;
+  out[1] += axis[1] * temp;
+  out[2] += axis[2] * temp;
+
+  cross_product(axis, vector, cross);
+
+  out[0] += cross[0] * sin_ang;
+  out[1] += cross[1] * sin_ang;
+  out[2] += cross[2] * sin_ang;
+}
+
+void BRDFRead::std_coords_to_half_diff_coords(double theta_in, double phi_in, double theta_out, double phi_out,
+                                              double &theta_half, double &phi_half, double &theta_diff,
+                                              double &phi_diff) {
+  // compute in vector
+  double in_vec_z = cos(theta_in);
+  double proj_in_vec = sin(theta_in);
+  double in_vec_x = proj_in_vec * cos(phi_in);
+  double in_vec_y = proj_in_vec * sin(phi_in);
+  double in[3] = {in_vec_x, in_vec_y, in_vec_z};
+  normalize(in);
+
+  // compute out vector
+  double out_vec_z = cos(theta_out);
+  double proj_out_vec = sin(theta_out);
+  double out_vec_x = proj_out_vec * cos(phi_out);
+  double out_vec_y = proj_out_vec * sin(phi_out);
+  double out[3] = {out_vec_x, out_vec_y, out_vec_z};
+  normalize(out);
+
+  // compute halfway vector
+  double half_x = (in_vec_x + out_vec_x) / 2.0f;
+  double half_y = (in_vec_y + out_vec_y) / 2.0f;
+  double half_z = (in_vec_z + out_vec_z) / 2.0f;
+  double half[3] = {half_x, half_y, half_z};
+  normalize(half);
+
+  // compute  theta_half, phi_half
+  theta_half = acos(half[2]);
+  phi_half = atan2(half[1], half[0]);
+
+  double bi_normal[3] = {0.0, 1.0, 0.0};
+  double normal[3] = {0.0, 0.0, 1.0};
+  double temp[3];
+  double diff[3];
+
+  // compute diff vector
+  rotate_vector(in, normal, -phi_half, temp);
+  rotate_vector(temp, bi_normal, -theta_half, diff);
+
+  // compute  theta_diff, phi_diff
+  theta_diff = acos(diff[2]);
+  phi_diff = atan2(diff[1], diff[0]);
+}
+
+int BRDFRead::theta_half_index(double theta_half) {
+  if (theta_half <= 0.0)
+    return 0;
+  double theta_half_deg = ((theta_half / (M_PI / 2.0)) * BRDF_SAMPLING_RES_THETA_H);
+  double temp = theta_half_deg * BRDF_SAMPLING_RES_THETA_H;
+  temp = sqrt(temp);
+  int ret_val = (int)temp;
+  if (ret_val < 0)
+    ret_val = 0;
+  if (ret_val >= BRDF_SAMPLING_RES_THETA_H)
+    ret_val = BRDF_SAMPLING_RES_THETA_H - 1;
+  return ret_val;
+}
+
+int BRDFRead::theta_diff_index(double theta_diff) {
+  int tmp = int(theta_diff / (M_PI * 0.5) * BRDF_SAMPLING_RES_THETA_D);
+  if (tmp < 0)
+    return 0;
+  else if (tmp < BRDF_SAMPLING_RES_THETA_D - 1)
+    return tmp;
+  else
+    return BRDF_SAMPLING_RES_THETA_D - 1;
+}
+
+int BRDFRead::phi_diff_index(double phi_diff) {
+  // Because of reciprocity, the BRDF is unchanged under
+  // phi_diff -> phi_diff + M_PI
+  if (phi_diff < 0.0)
+    phi_diff += M_PI;
+
+  // In: phi_diff in [0 .. pi]
+  // Out: tmp in [0 .. 179]
+  int tmp = int(phi_diff / M_PI * BRDF_SAMPLING_RES_PHI_D / 2);
+  if (tmp < 0)
+    return 0;
+  else if (tmp < BRDF_SAMPLING_RES_PHI_D / 2 - 1)
+    return tmp;
+  else
+    return BRDF_SAMPLING_RES_PHI_D / 2 - 1;
+}
diff --git a/common/brdfread.h b/common/brdfread.h
new file mode 100644
index 0000000..eb990a2
--- /dev/null
+++ b/common/brdfread.h
@@ -0,0 +1,100 @@
+// Copyright 2005 Mitsubishi Electric Research Laboratories All Rights Reserved.
+
+// Permission to use, copy and modify this software and its documentation without
+// fee for educational, research and non-profit purposes, is hereby granted, provided
+// that the above copyright notice and the following three paragraphs appear in all copies.
+
+// To request permission to incorporate this software into commercial products contact:
+// Vice President of Marketing and Business Development;
+// Mitsubishi Electric Research Laboratories (MERL), 201 Broadway, Cambridge, MA 02139 or
+// <license@merl.com>.
+
+// IN NO EVENT SHALL MERL BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL,
+// OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND
+// ITS DOCUMENTATION, EVEN IF MERL HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
+
+// MERL SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED
+// HEREUNDER IS ON AN "AS IS" BASIS, AND MERL HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT,
+// UPDATES, ENHANCEMENTS OR MODIFICATIONS.
+
+// The Implementation has been moved to "brdfread.cpp" for compatibility
+#ifndef BRDFREAD_H
+#define BRDFREAD_H
+
+#include <cmath>
+#include <common/color.h>
+#include <cstdlib>
+#include <iostream>
+
+#define BRDF_SAMPLING_RES_THETA_H 90
+#define BRDF_SAMPLING_RES_THETA_D 90
+#define BRDF_SAMPLING_RES_PHI_D 360
+
+#define RED_SCALE (1.0 / 1500.0)
+#define GREEN_SCALE (1.15 / 1500.0)
+#define BLUE_SCALE (1.66 / 1500.0)
+#ifndef M_PI
+#define M_PI 3.1415926535897932384626433832795
+#endif
+
+class BRDFRead {
+public:
+  BRDFRead(const char *filename);
+
+  /**
+   * Given a pair of incoming/outgoing angles, look up the BRDF.
+   */
+  Color lookupBrdfValues(double theta_in, double phi_in, double theta_out, double phi_out);
+
+private:
+  /**
+   * Read BRDF data
+   */
+  bool readBrdf(const char *filename);
+
+  /**
+   * cross product of two vectors
+   */
+  void cross_product(double *v1, double *v2, double *out);
+
+  /**
+   * normalize vector
+   */
+  void normalize(double *v);
+
+  /**
+   * rotate vector along one axis
+   */
+  void rotate_vector(double *vector, double *axis, double angle, double *out);
+
+  /**
+   * convert standard coordinates to half vector/difference vector coordinates
+   */
+  void std_coords_to_half_diff_coords(double theta_in, double phi_in, double theta_out, double phi_out,
+                                      double &theta_half, double &phi_half, double &theta_diff, double &phi_diff);
+
+  /**
+   * Lookup theta_half index
+   * This is a non-linear mapping!
+   * In:  [0 .. pi/2]
+   * Out: [0 .. 89]
+   */
+  inline int theta_half_index(double theta_half);
+
+  /**
+   * Lookup theta_diff index
+   * In:  [0 .. pi/2]
+   * Out: [0 .. 89]
+   */
+  inline int theta_diff_index(double theta_diff);
+
+  /**
+   * Lookup phi_diff index
+   */
+  inline int phi_diff_index(double phi_diff);
+
+  double *brdfData;
+};
+
+#endif
diff --git a/ex4.cpp b/ex4.cpp
new file mode 100644
index 0000000..cadf20c
--- /dev/null
+++ b/ex4.cpp
@@ -0,0 +1,74 @@
+#include <iostream>
+#include <string>
+
+#include "camera/perspectivecamera.h"
+#include "renderer/simplerenderer.h"
+#include "scene/simplescene.h"
+
+#include "primitive/box.h"
+#include "primitive/infiniteplane.h"
+#include "primitive/objmodel.h"
+#include "primitive/sphere.h"
+
+#include "shader/brdfshader.h"
+
+#include "shader/lambertshader.h"
+#include "shader/mirrorshader.h"
+#include "shader/phongshader.h"
+#include "shader/cooktorranceshader.h"
+
+#include "light/ambientlight.h"
+#include "light/pointlight.h"
+#include "light/spotlight.h"
+
+int main() {
+  // Let's create a simple scene...
+  SimpleScene scene;
+
+  // Add shaders
+  auto mirror = std::make_shared<MirrorShader>();
+  auto white = std::make_shared<LambertShader>(Color(0.9f, 0.9f, 0.9f));
+  auto red = std::make_shared<LambertShader>(Color(1.0f, 0.3f, 0.2f));
+  auto blue = std::make_shared<LambertShader>(Color(0.2f, 0.3f, 1.0f));
+  auto orange = std::make_shared<PhongShader>(Color(1.0f, 0.64f, 0.0f), 1.0f, Color(1.0f, 1.0f, 1.0f), 1.0f, 25.0f);
+  auto gold= std::make_shared<CookTorranceShader>(Color(0.83f, 0.69f, 0.22f), Color(1.0f, 1.0f, 0.0f), 1.2f, 0.2f);
+  auto blueMetallic = std::make_shared<BrdfShader>("data/blue-metallic-paint.binary", Color(7.0f, 7.0f, 7.0f));
+  auto darkRed = std::make_shared<BrdfShader>("data/dark-red-paint.binary", Color(7.0f, 7.0f, 7.0f));
+
+  // Set up the walls
+  // ---------------------------------------------------------------------------
+  scene.add(std::make_shared<InfinitePlane>(Vector3d(0.0f, 0.0f, +5.0f), Vector3d(0.0f, 0.0f, -1.0f), mirror));
+
+  scene.add(std::make_shared<InfinitePlane>(Vector3d(0.0f, 0.0f, -5.0f), Vector3d(0.0f, 0.0f, +1.0f), mirror));
+  scene.add(std::make_shared<InfinitePlane>(Vector3d(0.0f, +5.0f, 0.0f), Vector3d(0.0f, -1.0f, 0.0f), white));
+  scene.add(std::make_shared<InfinitePlane>(Vector3d(0.0f, -5.0f, 0.0f), Vector3d(0.0f, +1.0f, 0.0f), white));
+  scene.add(std::make_shared<InfinitePlane>(Vector3d(+5.0f, 0.0f, 0.0f), Vector3d(-1.0f, 0.0f, 0.0f), blue));
+  scene.add(std::make_shared<InfinitePlane>(Vector3d(-5.0f, 0.0f, 0.0f), Vector3d(+1.0f, 0.0f, 0.0f), red));
+
+  scene.add(std::make_shared<Sphere>(Vector3d(-3.0f, 0.0f, 0.0f), 1.0f, blueMetallic));
+  scene.add(std::make_shared<Sphere>(Vector3d(0.0f, 2.0f, 0.0f), 1.0f, orange));
+  scene.add(std::make_shared<Sphere>(Vector3d(3.0f, 0.0f, 0.0f), 1.0f, darkRed));
+
+  // Add the teapot
+  auto teapot = std::make_shared<ObjModel>(gold);
+  teapot->loadObj("data/teapot.obj", Vector3d(3.0f, 3.0f, 3.0f), Vector3d(0.0f, -5.0f, 0.0f));
+  scene.add(teapot);
+
+  // Add ambient light
+  scene.add(std::make_shared<AmbientLight>(0.15f));
+  scene.add(std::make_shared<PointLight>(Vector3d(0.0f, 4.0f, -4.0f), 15.0f));
+  scene.add(std::make_shared<PointLight>(Vector3d(0.0f, 4.0f, 4.0f), 15.0f));
+
+  // Set up the camera
+  PerspectiveCamera camera;
+  camera.setFovAngle(90.0f);
+  camera.setPosition(Vector3d(0.0f, 0.0f, -10.0f));
+  camera.setForwardDirection(Vector3d(0.0f, 0.0f, 1.0f));
+  camera.setUpDirection(Vector3d(0.0f, 1.0f, 0.0f));
+
+  // Render the scene
+  SimpleRenderer renderer;
+  renderer.renderImage(scene, camera, 512, 512).save("result.png");
+
+  return 0;
+}
diff --git a/primitive/triangle.cpp b/primitive/triangle.cpp
index b98c539..34da50a 100644
--- a/primitive/triangle.cpp
+++ b/primitive/triangle.cpp
@@ -100,6 +100,7 @@ bool Triangle::intersect(Ray &ray) const {
     return false;
 
   // Calculate the normal
+  // IMPLEMENT smooth triangles, if available
   ray.normal = normalized(crossProduct(edge1, edge2));
 
   // Calculate the surface position
diff --git a/shader/brdfshader.cpp b/shader/brdfshader.cpp
new file mode 100644
index 0000000..ab77d37
--- /dev/null
+++ b/shader/brdfshader.cpp
@@ -0,0 +1,13 @@
+#include "light/light.h"
+#include "scene/scene.h"
+#include "shader/brdfshader.h"
+
+BrdfShader::BrdfShader(char const *fileName, Color const &scale)
+    : scale(scale), brdf(std::make_unique<BRDFRead>(fileName)) {}
+
+Color BrdfShader::shade(Scene const &scene, Ray const &ray) const {
+  Color illuminationColor;
+
+  // IMPLEMENT ME
+  return illuminationColor;
+}
diff --git a/shader/brdfshader.h b/shader/brdfshader.h
new file mode 100644
index 0000000..250eb9f
--- /dev/null
+++ b/shader/brdfshader.h
@@ -0,0 +1,23 @@
+#ifndef BRDFSHADER_H
+#define BRDFSHADER_H
+
+#include "common/brdfread.h"
+#include "shader/shader.h"
+#include <memory>
+
+class BrdfShader : public Shader {
+
+public:
+  // Constructor
+  BrdfShader(char const *fileName, Color const &scale);
+  ~BrdfShader() override = default;
+
+  // Shader functions
+  Color shade(Scene const &scene, Ray const &ray) const override;
+
+private:
+  Color scale;
+  std::unique_ptr<BRDFRead> brdf;
+};
+
+#endif
diff --git a/shader/cooktorranceshader.cpp b/shader/cooktorranceshader.cpp
new file mode 100644
index 0000000..3f9cff5
--- /dev/null
+++ b/shader/cooktorranceshader.cpp
@@ -0,0 +1,13 @@
+#include "light/light.h"
+#include "scene/scene.h"
+#include "shader/cooktorranceshader.h"
+
+CookTorranceShader::CookTorranceShader(Color const &diffCol, Color const &ctCol, float IOR, float roughness, float diffCoeff, float ctCoeff) : diffuseColor(diffCol * diffCoeff), ctColor(ctCol * ctCoeff), F0(IOR), m(roughness) {}
+
+Color CookTorranceShader::shade(Scene const &scene, Ray const &ray) const {
+  Color fragmentColor;
+
+  // IMPLEMENT ME
+
+  return fragmentColor;
+}
\ No newline at end of file
diff --git a/shader/cooktorranceshader.h b/shader/cooktorranceshader.h
new file mode 100644
index 0000000..7c2844d
--- /dev/null
+++ b/shader/cooktorranceshader.h
@@ -0,0 +1,26 @@
+#ifndef COOKTORRANCESHADER_H
+#define COOKTORRANCESHADER_H
+
+#include "shader/shader.h"
+
+class CookTorranceShader : public Shader {
+public:
+  CookTorranceShader(Color const &diffuseColor, Color const &ctColor, float IOR, float roughness,
+                     float diffuseCoefficient = PI / 2.0f, float ctCoefficient = PI / 2.0f);
+  // Shader functions
+  Color shade(Scene const &scene, Ray const &ray) const override;
+
+private:
+  float D(float NdotH) const;
+  float F(float VdotH) const;
+  float G(float NdotH, float NdotV, float VdotH, float NdotL) const;
+
+  Color diffuseColor;
+
+  Color ctColor;
+
+  float F0;
+  float m;
+};
+
+#endif
\ No newline at end of file
diff --git a/shader/lambertshader.cpp b/shader/lambertshader.cpp
new file mode 100644
index 0000000..3aebacd
--- /dev/null
+++ b/shader/lambertshader.cpp
@@ -0,0 +1,13 @@
+#include "light/light.h"
+#include "scene/scene.h"
+#include "shader/lambertshader.h"
+
+LambertShader::LambertShader(Color const &diffuseColor) : diffuseColor(diffuseColor) {}
+
+Color LambertShader::shade(Scene const &scene, Ray const &ray) const {
+  Color fragmentColor;
+
+  // IMPLEMENT ME
+
+  return fragmentColor;
+}
diff --git a/shader/lambertshader.h b/shader/lambertshader.h
new file mode 100644
index 0000000..f5feb43
--- /dev/null
+++ b/shader/lambertshader.h
@@ -0,0 +1,19 @@
+#ifndef LAMBERTSHADER_H
+#define LAMBERTSHADER_H
+
+#include "shader/shader.h"
+
+class LambertShader : public Shader {
+
+public:
+  // Constructor
+  LambertShader(Color const &diffuseColor = Color(1, 1, 1));
+
+  // Shader functions
+  Color shade(Scene const &scene, Ray const &ray) const override;
+
+protected:
+  Color diffuseColor;
+};
+
+#endif
diff --git a/shader/phongshader.cpp b/shader/phongshader.cpp
new file mode 100644
index 0000000..da6d3e2
--- /dev/null
+++ b/shader/phongshader.cpp
@@ -0,0 +1,16 @@
+#include "light/light.h"
+#include "scene/scene.h"
+#include "shader/phongshader.h"
+
+PhongShader::PhongShader(Color const &diffuseColor, float diffuseCoefficient, Color const &specularColor,
+                         float specularCoefficient, float shininessExponent)
+    : diffuseColor(diffuseColor), diffuseCoefficient(diffuseCoefficient), specularColor(specularColor),
+      specularCoefficient(specularCoefficient), shininessExponent(shininessExponent) {}
+
+Color PhongShader::shade(Scene const &scene, Ray const &ray) const {
+  Color fragmentColor;
+
+  // IMPLEMENT ME
+
+  return fragmentColor;
+}
diff --git a/shader/phongshader.h b/shader/phongshader.h
new file mode 100644
index 0000000..81e4b5e
--- /dev/null
+++ b/shader/phongshader.h
@@ -0,0 +1,25 @@
+#ifndef PHONGSHADER_H
+#define PHONGSHADER_H
+
+#include "shader/shader.h"
+
+class PhongShader : public Shader {
+
+public:
+  // Constructor
+  PhongShader(Color const &diffuseColor, float diffuseCoefficient, Color const &specularColor,
+              float specularCoefficient, float shininessExponent);
+
+  // Shader functions
+  Color shade(Scene const &scene, Ray const &ray) const override;
+
+private:
+  Color diffuseColor;
+  float diffuseCoefficient;
+
+  Color specularColor;
+  float specularCoefficient;
+  float shininessExponent;
+};
+
+#endif