diff --git a/images/wall.png b/images/wall.png
new file mode 100644
index 0000000..1dd652b
Binary files /dev/null and b/images/wall.png differ
diff --git a/shaders/tag.fs b/shaders/tag.fs
index b738ab3..3c0a5aa 100644
--- a/shaders/tag.fs
+++ b/shaders/tag.fs
@@ -1,4 +1,23 @@
 #version 330
 
-void main() {
+in vec3 vsoNormal;
+in vec4 vsoModPos;
+
+in vec2 vsoTexCoord;
+
+out vec4 fragColor;
+
+uniform sampler2D tex0;
+uniform mat4 viewMatrix;
+uniform vec4 lumPos;
+
+void main(void) {
+  const vec3 Vu = vec3(0, 0, -1);
+  vec4 lumPosv = viewMatrix * lumPos;
+  vec3 Ld = normalize(vsoModPos - lumPosv).xyz;
+  vec3 reflexion = normalize(reflect(Ld, vsoNormal));
+  float ispec = pow(clamp(dot(-Vu, reflexion), 0., 1.), 20);
+  float phongIL = clamp(dot(-Ld, vsoNormal), 0., 1.);
+
+  fragColor = phongIL * texture(tex0, vsoTexCoord) + ispec * vec4(1);
 }
diff --git a/shaders/tag.vs b/shaders/tag.vs
index b738ab3..18bdf67 100644
--- a/shaders/tag.vs
+++ b/shaders/tag.vs
@@ -1,4 +1,33 @@
 #version 330
 
-void main() {
+layout(location = 0) in vec3 vsiPosition;
+layout(location = 1) in vec3 vsiNormal;
+layout(location = 2) in vec2 vsiTexCoord;
+
+out vec2 vsoTexCoord;
+out vec3 vsoNormal;
+out vec4 vsoModPos;
+out float vsoIntensiteLum;
+
+uniform mat4 proj, model, view;
+
+uniform vec4 lumPos;
+uniform float phase;
+
+void main(void) {
+  mat4 N = transpose(inverse(view * model));
+  vsoNormal = normalize((N * vec4(vsiNormal, 0)).xyz);
+  vec4 lumPosv = view * lumPos;
+
+  float dist = length(vsiPosition.xz), freq = 5, amplitude = 0.1 * (sqrt(2.) - dist);
+  float y = amplitude * cos(phase + freq * dist);
+  vec3 p = vec3(vsiPosition.x, y, vsiPosition.z);
+
+  vsoModPos = view * model * vec4(p, 1);
+  vec3 Ld = normalize(vsoModPos - lumPosv).xyz;
+
+  vsoIntensiteLum = clamp(dot(-Ld, vsoNormal), 0., 1.);
+  gl_Position = proj * vsoModPos;
+
+  vsoTexCoord = vec2(vsiTexCoord.x, 1 - vsiTexCoord.y);
 }
diff --git a/src/tag.c b/src/tag.c
index 0ec10c2..99d99c2 100644
--- a/src/tag.c
+++ b/src/tag.c
@@ -1,9 +1,16 @@
 #include "../includes/animations.h"
 
 static GLuint _pId = 0;
+static GLuint _murId = 0;
+static GLuint _texId = 0;
+
+static const char *matrix_proj = "proj";
+static const char *matrix_model = "model";
+static const char *matrix_view = "view";
 
 static void init(void);
 static void draw(void);
+static void deinit(void);
 
 void tag(int state) {
   switch (state) {
@@ -15,20 +22,71 @@ void tag(int state) {
     draw();
     break;
 
+  case GL4DH_FREE:
+    deinit();
+    break;
+
   default:
     break;
   }
 }
 
 static void init(void) {
+  _murId = gl4dgGenGrid2df(100, 100);
   _pId = gl4duCreateProgram("<vs>shaders/tag.vs", "<fs>shaders/tag.fs", NULL);
+
+  glGenTextures(1, &_texId);
+  load_img("images/wall.png", _texId);
+
+  gl4duGenMatrix(GL_FLOAT, matrix_proj);
+  gl4duGenMatrix(GL_FLOAT, matrix_model);
+  gl4duGenMatrix(GL_FLOAT, matrix_view);
 }
 
 static void draw(void) {
+  static double t0 = 0;
+  float dt = (float)get_dt(&t0, GL_TRUE);
+
+  static GLfloat angle = 0.0f;
+  GLfloat lum_pos[] = {-2.0f *
+                           (float)cos(angle * (GLfloat)M_PI / (5.0f * 180.0f)),
+                       0.2f, 0.0f, 1.0f};
+
   glEnable(GL_DEPTH_TEST);
   glClearColor(0.2f, 0.2f, 0.2f, 1);
   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
   glUseProgram(_pId);
 
+  bindAndLoadf(matrix_proj);
+  GLfloat ratio = (GLfloat)_dims[0] / (GLfloat)_dims[1];
+  gl4duFrustumf(-1, 1, -ratio, ratio, 2, 1000);
+
+  bindAndLoadf(matrix_view);
+  const GLfloat distance = 2; // distance from the scene
+  gl4duLookAtf(0, distance, distance, 0, 0, 0, 0, 1, 0);
+  // gl4duRotatef(-90, 0, 1, 0); // rotation camera
+
+  bindAndLoadf(matrix_model);
+  gl4duRotatef(40, 1, 0, 0);
+  gl4duRotatef(40, 0, 0, 1);
+
+  angle += dt * 90.0f;
+  gl4duSendMatrices();
+
+  glActiveTexture(GL_TEXTURE0);
+  glBindTexture(GL_TEXTURE_2D, _texId);
+  glUniform1f(glGetUniformLocation(_pId, "phase"), 0);
+  glUniform4fv(glGetUniformLocation(_pId, "lumPos"), 1, lum_pos);
+
+  gl4dgDraw(_murId);
+
   glUseProgram(0);
+  glBindTexture(GL_TEXTURE_2D, 0);
+}
+
+static void deinit(void) {
+  if (_texId) {
+    glDeleteTextures(1, &_texId);
+    _texId = 0;
+  }
 }