diff --git a/3-mid/opengl/assets/shader/lit_textured_skinned.frag b/3-mid/opengl/assets/shader/lighting-frag.snippet
similarity index 61%
rename from 3-mid/opengl/assets/shader/lit_textured_skinned.frag
rename to 3-mid/opengl/assets/shader/lighting-frag.snippet
index d39eb5b..a04744e 100644
--- a/3-mid/opengl/assets/shader/lit_textured_skinned.frag
+++ b/3-mid/opengl/assets/shader/lighting-frag.snippet
@@ -1,4 +1,5 @@
-#version 140
+
+
 
 struct light
 {
@@ -11,21 +12,13 @@ struct light
 };
 
 
-uniform mat4        model_Transform;
-uniform mat3        inverse_model_Rotation;
-uniform vec3        camera_Site;
-uniform vec3        specular_Color;    // The materials specular color.
-uniform sampler2D   Texture;
+
 uniform int         light_Count;
-uniform light       Lights [10];
+uniform light       Lights [50];
+uniform vec3        specular_Color;     // The materials specular color.
 
+in      float       frag_Shine;
 
-in  vec3   frag_Site;
-in  vec3   frag_Normal;
-in  vec2   frag_Coords;
-in  float  frag_Shine;
-
-out vec4   final_Color;
 
 
 vec3
@@ -77,12 +70,15 @@ apply_Light (light   Light,
     vec3    Diffuse              = diffuse_Coefficient * lit_surface_Color;
     float   specular_Coefficient = 0.0;
 
+
     if (diffuse_Coefficient > 0.0)
+    {
         specular_Coefficient = pow (max (0.0, 
                                          dot (Surface_to_Camera, 
                                               reflect (-Surface_to_Light,
                                                        Normal))),
                                     frag_Shine);
+    }
 
     vec3   Specular = specular_Coefficient * specular_Color * Light.Color;
 
@@ -91,34 +87,3 @@ apply_Light (light   Light,
 
 
 
-void
-main()
-{
-    vec3   surface_Site      = vec3 (  model_Transform
-                                     * vec4 (frag_Site, 1));
-                                   
-    vec4   surface_Color     = texture (Texture, frag_Coords);
-
-    vec3   Surface_to_Camera = normalize (camera_Site - surface_Site);
-    vec3   Normal            = normalize (  frag_Normal
-                                          * inverse_model_Rotation);
-
-    // Combine color from all the lights.
-    //
-    vec3   linear_Color = vec3 (0);
-    
-    for (int i = 0;   i < light_Count;   ++i)
-    {
-        linear_Color += apply_Light (Lights [i],
-                                     surface_Color.rgb,
-                                     Normal,
-                                     surface_Site,
-                                     Surface_to_Camera);
-    }
-    
-    vec3   Gamma = vec3 (1.0 / 2.2);
-
-    final_Color = vec4 (pow (linear_Color,     // Final color (after gamma correction).
-                             Gamma),
-                        surface_Color.a);
-}
\ No newline at end of file
diff --git a/3-mid/opengl/assets/shader/lit_colored.frag b/3-mid/opengl/assets/shader/lit_colored.frag
index 28a839c..83f37c9 100644
--- a/3-mid/opengl/assets/shader/lit_colored.frag
+++ b/3-mid/opengl/assets/shader/lit_colored.frag
@@ -1,92 +1,17 @@
-#version 140
-
-struct light
-{
-   vec4    Site;
-   vec3    Color;
-   float   Attenuation;
-   float   ambient_Coefficient;
-   float   cone_Angle;
-   vec3    cone_Direction;
-};
+// Include 'version.header'.
+// Include 'lighting-frag.snippet'
 
 
-uniform mat4    model_Transform;
-uniform mat3    inverse_model_Rotation;
-uniform vec3    camera_Site;
-uniform vec3    specular_Color;    // The materials specular color.
-uniform int     light_Count;
-uniform light   Lights [50];
 
+in  vec3       frag_Site;
+in  vec3       frag_Normal;
+in  vec4       frag_Color;
 
-in  vec3   frag_Site;
-in  vec3   frag_Normal;
-in  vec4   frag_Color;
-in  float  frag_Shine;
+uniform mat4   model_Transform;
+uniform mat3   inverse_model_Rotation;
+uniform vec3   camera_Site;
 
-out vec4   final_Color;
-
-
-vec3
-apply_Light (light   Light, 
-             vec3    surface_Color, 
-             vec3    Normal, 
-             vec3    surface_Site, 
-             vec3    Surface_to_Camera)
-{
-    vec3    Surface_to_Light;
-    float   Attenuation = 1.0;
-    
-    if (Light.Site.w == 0.0)
-    {
-        // Directional light.
-        //
-        Surface_to_Light = normalize (-Light.Site.xyz);
-        Attenuation      = 1.0;     // No attenuation for directional lights.
-    } 
-    else
-    {
-        // Point light.
-        //
-        vec3    Surface_to_Light_vector = Light.Site.xyz - surface_Site;
-        float   Distance_to_Light       = length (Surface_to_Light_vector);
-
-        Surface_to_Light = normalize (Surface_to_Light_vector);
-        Attenuation      =   1.0
-                           / (  1.0 
-                              +   Light.Attenuation
-                                * pow (Distance_to_Light, 2));
-
-        // Cone restrictions which affects attenuation.
-        //
-        float   Light_to_Surface_Angle = degrees (acos (dot (-Surface_to_Light, 
-                                                             normalize (Light.cone_Direction))));
-        
-        if (Light_to_Surface_Angle > Light.cone_Angle)
-        {
-            Attenuation = 0.0;
-        }
-    }
-
-    vec3    lit_surface_Color    = surface_Color * Light.Color;
-    vec3    Ambient              = Light.ambient_Coefficient * lit_surface_Color;
-    float   diffuse_Coefficient  = max (0.0, 
-                                        dot (Normal,
-                                             Surface_to_Light));                   
-    vec3    Diffuse              = diffuse_Coefficient * lit_surface_Color;
-    float   specular_Coefficient = 0.0;
-
-    if (diffuse_Coefficient > 0.0)
-        specular_Coefficient = pow (max (0.0, 
-                                         dot (Surface_to_Camera, 
-                                              reflect (-Surface_to_Light,
-                                                       Normal))),
-                                    frag_Shine);
-
-    vec3   Specular = specular_Coefficient * specular_Color * Light.Color;
-
-    return Ambient + Attenuation * (Diffuse + Specular);     // Linear color (before gamma correction).
-}
+out vec4       final_Color;
 
 
 
@@ -120,4 +45,7 @@ main()
     final_Color = vec4 (pow (linear_Color,     // Final color (after gamma correction).
                              Gamma),
                         surface_Color.a);
+  
+    final_Color = min (final_Color,            // Prevent light saturation.
+                       surface_Color);
 }
\ No newline at end of file
diff --git a/3-mid/opengl/assets/shader/lit_colored_skinned.frag b/3-mid/opengl/assets/shader/lit_colored_skinned.frag
index dcc45de..422287b 100644
--- a/3-mid/opengl/assets/shader/lit_colored_skinned.frag
+++ b/3-mid/opengl/assets/shader/lit_colored_skinned.frag
@@ -1,106 +1,26 @@
-#version 140
-
-struct light
-{
-   vec4    Site;
-   vec3    Color;
-   float   Attenuation;
-   float   ambient_Coefficient;
-   float   cone_Angle;
-   vec3    cone_Direction;
-};
+// Include 'version.header'.
+// Include 'lighting-frag.snippet'
 
 
-uniform mat4        model_Transform;
-uniform mat3        inverse_model_Rotation;
-uniform vec3        camera_Site;
-uniform vec3        specular_Color;    // The materials specular color.
-uniform sampler2D   Texture;
-uniform int         light_Count;
-uniform light       Lights [50];
 
+in  vec3       frag_Site;
+in  vec3       frag_Normal;
+in  vec4       frag_Color;
 
-in  vec3   frag_Site;
-in  vec3   frag_Normal;
-in  vec4   frag_Color;
-in  vec2   frag_Coords;
-in  float  frag_Shine;
+uniform mat4   model_Transform;
+uniform mat3   inverse_model_Rotation;
+uniform vec3   camera_Site;
 
-out vec4   final_Color;
-
-
-vec3
-apply_Light (light   Light, 
-             vec3    surface_Color, 
-             vec3    Normal, 
-             vec3    surface_Site, 
-             vec3    Surface_to_Camera)
-{
-    vec3    Surface_to_Light;
-    float   Attenuation = 1.0;
-    
-    if (Light.Site.w == 0.0)
-    {
-        // Directional light.
-        //
-        Surface_to_Light = normalize (-Light.Site.xyz);
-        Attenuation      = 1.0;     // No attenuation for directional lights.
-    } 
-    else
-    {
-        // Point light.
-        //
-        vec3    Surface_to_Light_vector = Light.Site.xyz - surface_Site;
-        float   Distance_to_Light       = length (Surface_to_Light_vector);
-
-        Surface_to_Light = normalize (Surface_to_Light_vector);
-        Attenuation      =   1.0
-                           / (  1.0 
-                              +   Light.Attenuation
-                                * pow (Distance_to_Light, 2));
-
-        // Cone restrictions which affects attenuation.
-        //
-        float   Light_to_Surface_Angle = degrees (acos (dot (-Surface_to_Light, 
-                                                             normalize (Light.cone_Direction))));
-        
-        if (Light_to_Surface_Angle > Light.cone_Angle)
-        {
-            Attenuation = 0.0;
-        }
-    }
-
-    vec3    lit_surface_Color    = surface_Color * Light.Color;
-    vec3    Ambient              = Light.ambient_Coefficient * lit_surface_Color;
-    float   diffuse_Coefficient  = max (0.0, 
-                                        dot (Normal,
-                                             Surface_to_Light));                   
-    vec3    Diffuse              = diffuse_Coefficient * lit_surface_Color;
-    float   specular_Coefficient = 0.0;
-
-    if (diffuse_Coefficient > 0.0)
-        specular_Coefficient = pow (max (0.0, 
-                                         dot (Surface_to_Camera, 
-                                              reflect (-Surface_to_Light,
-                                                       Normal))),
-                                    frag_Shine);
-
-    vec3   Specular = specular_Coefficient * specular_Color * Light.Color;
-
-    return Ambient + Attenuation * (Diffuse + Specular);     // Linear color (before gamma correction).
-}
+out vec4       final_Color;
 
 
 
 void
 main()
 {
-    vec3   surface_Site    = vec3 (  model_Transform
-                                   * vec4 (frag_Site, 1));
-                                   
-    vec4   surface_Color   =   (  texture  (Texture, frag_Coords)
-                                + frag_Color)
-                             / 2.0;
+    vec3   surface_Site      = vec3 (  model_Transform
+                                     * vec4 (frag_Site, 1));
+    vec4   surface_Color     = frag_Color;
 
     vec3   Surface_to_Camera = normalize (camera_Site - surface_Site);
     vec3   Normal            = normalize (  frag_Normal
@@ -124,4 +44,7 @@ main()
     final_Color = vec4 (pow (linear_Color,     // Final color (after gamma correction).
                              Gamma),
                         surface_Color.a);
+                                                
+    final_Color = min (final_Color,            // Prevent light saturation.
+                       surface_Color);
 }
\ No newline at end of file
diff --git a/3-mid/opengl/assets/shader/lit_colored_textured.frag b/3-mid/opengl/assets/shader/lit_colored_textured.frag
index 8ef83e1..cb2fa26 100644
--- a/3-mid/opengl/assets/shader/lit_colored_textured.frag
+++ b/3-mid/opengl/assets/shader/lit_colored_textured.frag
@@ -1,124 +1,19 @@
-#version 140
-
-
-// Texturing snippet.
-//
-uniform int         texture_Count;
-uniform sampler2D   Textures [32];
-uniform float       Fade     [32];
-
-vec4
-apply_Texturing (vec2   Coords)
-{
-    vec4   Color = vec4 (0);
-    
-    for (int i = 0;   i < texture_Count;   ++i)
-    {
-        Color.rgb +=   texture (Textures [i], Coords).rgb
-                     * texture (Textures [i], Coords).a
-                     * (1.0 - Fade [i]);
-                                      
-        Color.a    = max (Color.a, texture (Textures [i],
-                                            Coords).a);
-    }
-    
-    return Color;
-}
+// Include 'version.header'.
+// Include 'texturing-frag.snippet'.
+// Include 'lighting-frag.snippet'
 
 
 
-struct light
-{
-   vec4    Site;
-   vec3    Color;
-   float   Attenuation;
-   float   ambient_Coefficient;
-   float   cone_Angle;
-   vec3    cone_Direction;
-};
+in  vec3       frag_Site;
+in  vec3       frag_Normal;
+in  vec4       frag_Color;
+in  vec2       frag_Coords;
 
+uniform mat4   model_Transform;
+uniform mat3   inverse_model_Rotation;
+uniform vec3   camera_Site;
 
-uniform mat4        model_Transform;
-uniform mat3        inverse_model_Rotation;
-uniform vec3        camera_Site;
-uniform vec3        specular_Color;    // The materials specular color.
-//uniform sampler2D   Texture;
-uniform int         light_Count;
-uniform light       Lights [50];
-
-
-in  vec3   frag_Site;
-in  vec3   frag_Normal;
-in  vec4   frag_Color;
-in  vec2   frag_Coords;
-in  float  frag_Shine;
-
-out vec4   final_Color;
-
-
-
-
-vec3
-apply_Light (light   Light, 
-             vec3    surface_Color, 
-             vec3    Normal, 
-             vec3    surface_Site, 
-             vec3    Surface_to_Camera)
-{
-    vec3    Surface_to_Light;
-    float   Attenuation = 1.0;
-    
-    if (Light.Site.w == 0.0)
-    {
-        // Directional light.
-        //
-        Surface_to_Light = normalize (-Light.Site.xyz);
-        Attenuation      = 1.0;     // No attenuation for directional lights.
-    } 
-    else
-    {
-        // Point light.
-        //
-        vec3    Surface_to_Light_vector = Light.Site.xyz - surface_Site;
-        float   Distance_to_Light       = length (Surface_to_Light_vector);
-
-        Surface_to_Light = normalize (Surface_to_Light_vector);
-        Attenuation      =   1.0
-                           / (  1.0 
-                              +   Light.Attenuation
-                                * pow (Distance_to_Light, 2));
-
-        // Cone restrictions which affects attenuation.
-        //
-        float   Light_to_Surface_Angle = degrees (acos (dot (-Surface_to_Light, 
-                                                             normalize (Light.cone_Direction))));
-        
-        if (Light_to_Surface_Angle > Light.cone_Angle)
-        {
-            Attenuation = 0.0;
-        }
-    }
-
-    vec3    lit_surface_Color    = surface_Color * Light.Color;
-    vec3    Ambient              = Light.ambient_Coefficient * lit_surface_Color;
-    float   diffuse_Coefficient  = max (0.0, 
-                                        dot (Normal,
-                                             Surface_to_Light));                   
-    vec3    Diffuse              = diffuse_Coefficient * lit_surface_Color;
-    float   specular_Coefficient = 0.0;
-
-    if (diffuse_Coefficient > 0.0)
-        specular_Coefficient = pow (max (0.0, 
-                                         dot (Surface_to_Camera, 
-                                              reflect (-Surface_to_Light,
-                                                       Normal))),
-                                    frag_Shine);
-
-    vec3   Specular = specular_Coefficient * specular_Color * Light.Color;
-
-    return Ambient + Attenuation * (Diffuse + Specular);     // Linear color (before gamma correction).
-}
-
+out vec4       final_Color;
 
 
 
@@ -150,4 +45,7 @@ main()
     final_Color = vec4 (pow (linear_Color,     // Final color (after gamma correction).
                              Gamma),
                         surface_Color.a);
+
+    final_Color = min (final_Color,            // Prevent light saturation.
+                       surface_Color);
 }
\ No newline at end of file
diff --git a/3-mid/opengl/assets/shader/lit_colored_textured_skinned.frag b/3-mid/opengl/assets/shader/lit_colored_textured_skinned.frag
deleted file mode 100644
index 97f3cf7..0000000
--- a/3-mid/opengl/assets/shader/lit_colored_textured_skinned.frag
+++ /dev/null
@@ -1,127 +0,0 @@
-#version 140
-
-struct light
-{
-   vec4    Site;
-   vec3    Color;
-   float   Attenuation;
-   float   ambient_Coefficient;
-   float   cone_Angle;
-   vec3    cone_Direction;
-};
-
-
-uniform mat4        model_Transform;
-uniform mat3        inverse_model_Rotation;
-uniform vec3        camera_Site;
-uniform vec3        specular_Color;    // The materials specular color.
-uniform sampler2D   Texture;
-uniform int         light_Count;
-uniform light       Lights [50];
-
-
-in  vec3   frag_Site;
-in  vec3   frag_Normal;
-in  vec4   frag_Color;
-in  vec2   frag_Coords;
-in  float  frag_Shine;
-
-out vec4   final_Color;
-
-
-vec3
-apply_Light (light   Light, 
-             vec3    surface_Color, 
-             vec3    Normal, 
-             vec3    surface_Site, 
-             vec3    Surface_to_Camera)
-{
-    vec3    Surface_to_Light;
-    float   Attenuation = 1.0;
-    
-    if (Light.Site.w == 0.0)
-    {
-        // Directional light.
-        //
-        Surface_to_Light = normalize (-Light.Site.xyz);
-        Attenuation      = 1.0;     // No attenuation for directional lights.
-    } 
-    else
-    {
-        // Point light.
-        //
-        vec3    Surface_to_Light_vector = Light.Site.xyz - surface_Site;
-        float   Distance_to_Light       = length (Surface_to_Light_vector);
-
-        Surface_to_Light = normalize (Surface_to_Light_vector);
-        Attenuation      =   1.0
-                           / (  1.0 
-                              +   Light.Attenuation
-                                * pow (Distance_to_Light, 2));
-
-        // Cone restrictions which affects attenuation.
-        //
-        float   Light_to_Surface_Angle = degrees (acos (dot (-Surface_to_Light, 
-                                                             normalize (Light.cone_Direction))));
-        
-        if (Light_to_Surface_Angle > Light.cone_Angle)
-        {
-            Attenuation = 0.0;
-        }
-    }
-
-    vec3    lit_surface_Color    = surface_Color * Light.Color;
-    vec3    Ambient              = Light.ambient_Coefficient * lit_surface_Color;
-    float   diffuse_Coefficient  = max (0.0, 
-                                        dot (Normal,
-                                             Surface_to_Light));                   
-    vec3    Diffuse              = diffuse_Coefficient * lit_surface_Color;
-    float   specular_Coefficient = 0.0;
-
-    if (diffuse_Coefficient > 0.0)
-        specular_Coefficient = pow (max (0.0, 
-                                         dot (Surface_to_Camera, 
-                                              reflect (-Surface_to_Light,
-                                                       Normal))),
-                                    frag_Shine);
-
-    vec3   Specular = specular_Coefficient * specular_Color * Light.Color;
-
-    return Ambient + Attenuation * (Diffuse + Specular);     // Linear color (before gamma correction).
-}
-
-
-
-void
-main()
-{
-    vec3   surface_Site    = vec3 (  model_Transform
-                                   * vec4 (frag_Site, 1));
-                                   
-    vec4   surface_Color   = mix (texture (Texture, frag_Coords),
-                                  frag_Color,
-                                  0.5);
-
-    vec3   Surface_to_Camera = normalize (camera_Site - surface_Site);
-    vec3   Normal            = normalize (  frag_Normal
-                                          * inverse_model_Rotation);
-
-    // Combine color from all the lights.
-    //
-    vec3   linear_Color = vec3 (0);
-    
-    for (int i = 0;   i < light_Count;   ++i)
-    {
-        linear_Color += apply_Light (Lights [i],
-                                     surface_Color.rgb,
-                                     Normal,
-                                     surface_Site,
-                                     Surface_to_Camera);
-    }
-    
-    vec3   Gamma = vec3 (1.0 / 2.2);
-
-    final_Color = vec4 (pow (linear_Color,     // Final color (after gamma correction).
-                             Gamma),
-                        surface_Color.a);
-}
\ No newline at end of file
diff --git a/3-mid/opengl/assets/shader/lit_textured.frag b/3-mid/opengl/assets/shader/lit_textured.frag
index 3a85275..b8b2483 100644
--- a/3-mid/opengl/assets/shader/lit_textured.frag
+++ b/3-mid/opengl/assets/shader/lit_textured.frag
@@ -1,98 +1,18 @@
 // Include 'version.header'.
-// Include 'texturing.frag'.
-
-
-struct light
-{
-   vec4    Site;
-   vec3    Color;
-   float   Attenuation;
-   float   ambient_Coefficient;
-   float   cone_Angle;
-   vec3    cone_Direction;
-};
-
-
-uniform mat4        model_Transform;
-uniform mat3        inverse_model_Rotation;
-uniform vec3        camera_Site;
-uniform vec3        specular_Color;    // The materials specular color.
-
-uniform int         light_Count;
-uniform light       Lights [50];
-
-
-in  vec3   frag_Site;
-in  vec3   frag_Normal;
-in  vec2   frag_Coords;
-in  float  frag_Shine;
-
-out vec4   final_Color;
+// Include 'texturing-frag.snippet'.
+// Include 'lighting-frag.snippet'
 
 
 
+in  vec3       frag_Site;
+in  vec3       frag_Normal;
+in  vec2       frag_Coords;
 
-vec3
-apply_Light (light   Light, 
-             vec3    surface_Color, 
-             vec3    Normal, 
-             vec3    surface_Site, 
-             vec3    Surface_to_Camera)
-{
-    vec3    Surface_to_Light;
-    float   Attenuation = 1.0;
-    
-    if (Light.Site.w == 0.0)
-    {
-        // Directional light.
-        //
-        Surface_to_Light = normalize (-Light.Site.xyz);
-        Attenuation      = 1.0;     // No attenuation for directional lights.
-    } 
-    else
-    {
-        // Point light.
-        //
-        vec3    Surface_to_Light_vector = Light.Site.xyz - surface_Site;
-        float   Distance_to_Light       = length (Surface_to_Light_vector);
-
-        Surface_to_Light = normalize (Surface_to_Light_vector);
-        Attenuation      =   1.0
-                           / (  1.0 
-                              +   Light.Attenuation
-                                * pow (Distance_to_Light, 2));
-
-        // Cone restrictions which affects attenuation.
-        //
-        float   Light_to_Surface_Angle = degrees (acos (dot (-Surface_to_Light, 
-                                                             normalize (Light.cone_Direction))));
-        
-        if (Light_to_Surface_Angle > Light.cone_Angle)
-        {
-            Attenuation = 0.0;
-        }
-    }
-
-    vec3    lit_surface_Color    = surface_Color * Light.Color;
-    vec3    Ambient              = Light.ambient_Coefficient * lit_surface_Color;
-    float   diffuse_Coefficient  = max (0.0, 
-                                        dot (Normal,
-                                             Surface_to_Light));                   
-    vec3    Diffuse              = diffuse_Coefficient * lit_surface_Color;
-    float   specular_Coefficient = 0.0;
-
-    if (diffuse_Coefficient > 0.0)
-        specular_Coefficient = pow (max (0.0, 
-                                         dot (Surface_to_Camera, 
-                                              reflect (-Surface_to_Light,
-                                                       Normal))),
-                                    frag_Shine);
-
-    vec3   Specular = specular_Coefficient * specular_Color * Light.Color;
-
-    return Ambient + Attenuation * (Diffuse + Specular);     // Linear color (before gamma correction).
-}
+uniform mat4   model_Transform;
+uniform mat3   inverse_model_Rotation;
+uniform vec3   camera_Site;
 
+out vec4       final_Color;
 
 
 
@@ -118,8 +38,12 @@ main()
                                      Surface_to_Camera);
     }
     
-    vec3  Gamma = vec3 (1.0 / 2.2);
+    vec3   Gamma = vec3 (1.0 / 2.2);
+    
     final_Color = vec4 (pow (linear_Color,     // Final color (after gamma correction).
                              Gamma),
                         surface_Color.a);
+                        
+    final_Color = min (final_Color,            // Prevent light saturation.
+                       surface_Color);
 }
\ No newline at end of file
diff --git a/3-mid/opengl/assets/shader/texturing-frag.snippet b/3-mid/opengl/assets/shader/texturing-frag.snippet
new file mode 100644
index 0000000..a527409
--- /dev/null
+++ b/3-mid/opengl/assets/shader/texturing-frag.snippet
@@ -0,0 +1,27 @@
+uniform int         texture_Count;
+uniform sampler2D   Textures [32];
+uniform float       Fade     [32];
+
+vec4
+apply_Texturing (vec2   Coords)
+{
+    vec4   Color = vec4 (0);
+
+    for (int i = 0;   i < texture_Count;   ++i)
+    {
+        Color.rgb +=   texture (Textures [i], Coords).rgb
+                     * texture (Textures [i], Coords).a
+                     * (1.0 - Fade [i]);
+                                      
+//        Color.a    += texture (Textures [i],  Coords).a * (1.0 - Fade[1]);
+
+        Color.a    = max (Color.a,
+                          texture (Textures [i],Coords).a * (1.0 - Fade[i]));
+
+
+//        Color.a    = max (Color.a,
+//                            texture (Textures [i],Coords).a);
+    }
+    
+    return Color;
+}
\ No newline at end of file
diff --git a/3-mid/opengl/source/demo/opengl-demo.adb b/3-mid/opengl/source/demo/opengl-demo.adb
index ff8ecce..0c3216d 100644
--- a/3-mid/opengl/source/demo/opengl-demo.adb
+++ b/3-mid/opengl/source/demo/opengl-demo.adb
@@ -109,7 +109,8 @@ is
          the_Light : openGL.Light.item := Demo.Renderer.new_Light;
       begin
          the_Light. Site_is ([5_000.0, 2_000.0, 5_000.0]);
-         the_Light.Color_is (White);
+         the_Light.Color_is (Grey);
+         --  the_Light.Color_is (Black);
 
          Demo.Renderer.set (the_Light);
       end;
@@ -271,7 +272,7 @@ is
       heights_File : constant asset_Name := to_Asset ("assets/opengl/terrain/kidwelly-terrain.png");
       texture_File : constant asset_Name := to_Asset ("assets/opengl/terrain/kidwelly-terrain-texture.png");
 
-      the_Region   : constant IO.height_Map_view   := IO.to_height_Map (heights_File, 10.0);
+      the_Region   : constant IO.height_Map_view   := IO.to_height_Map (heights_File, Scale => 10.0);
       Tiling       : constant texture_Transform_2d := (S => (0.0, 1.0),
                                                        T => (0.0, 1.0));
       the_ground_Model : constant Model.terrain.view
diff --git a/3-mid/opengl/source/lean/geometry/opengl-geometry-lit_colored.adb b/3-mid/opengl/source/lean/geometry/opengl-geometry-lit_colored.adb
index ba6c3e1..3c0a877 100644
--- a/3-mid/opengl/source/lean/geometry/opengl-geometry-lit_colored.adb
+++ b/3-mid/opengl/source/lean/geometry/opengl-geometry-lit_colored.adb
@@ -77,8 +77,10 @@ is
       begin
          the_Program.Program := new openGL.Program.lit.item;
 
-         the_Program.  vertex_Shader.define (Shader.Vertex,    "assets/opengl/shader/lit_colored.vert");
-         the_Program.fragment_Shader.define (Shader.Fragment,  "assets/opengl/shader/lit_colored.frag");
+         the_Program.  vertex_Shader.define (Shader.Vertex,   "assets/opengl/shader/lit_colored.vert");
+         the_Program.fragment_Shader.define (Shader.Fragment, (asset_Names' (1 => to_Asset ("assets/opengl/shader/version.header"),
+                                                                             2 => to_Asset ("assets/opengl/shader/lighting-frag.snippet"),
+                                                                             3 => to_Asset ("assets/opengl/shader/lit_colored.frag"))));
 
          the_Program.Program.define (the_Program.  vertex_Shader'Access,
                                      the_Program.fragment_Shader'Access);
diff --git a/3-mid/opengl/source/lean/geometry/opengl-geometry-lit_colored_skinned.adb b/3-mid/opengl/source/lean/geometry/opengl-geometry-lit_colored_skinned.adb
index 03f585d..15af306 100644
--- a/3-mid/opengl/source/lean/geometry/opengl-geometry-lit_colored_skinned.adb
+++ b/3-mid/opengl/source/lean/geometry/opengl-geometry-lit_colored_skinned.adb
@@ -102,7 +102,7 @@ is
 
       if is_Defined
       then
-         raise Error with "The lit_colored_textured_skinned program has already been defined.";
+         raise Error with "The 'lit_colored_textured_skinned' program has already been defined.";
       end if;
 
       is_Defined := True;
@@ -110,8 +110,9 @@ is
       -- Define the shaders and program.
       --
       vertex_Shader  .define (Shader.Vertex,   "assets/opengl/shader/lit_colored_skinned.vert");
-      fragment_Shader.define (Shader.Fragment, "assets/opengl/shader/lit_colored_skinned.frag");
-
+      fragment_Shader.define (Shader.Fragment, (asset_Names' (1 => to_Asset ("assets/opengl/shader/version.header"),
+                                                              2 => to_Asset ("assets/opengl/shader/lighting-frag.snippet"),
+                                                              3 => to_Asset ("assets/opengl/shader/lit_colored_skinned.frag"))));
       the_Program.define (  vertex_Shader'Access,
                           fragment_Shader'Access);
       the_Program.enable;
diff --git a/3-mid/opengl/source/lean/geometry/opengl-geometry-lit_colored_textured.adb b/3-mid/opengl/source/lean/geometry/opengl-geometry-lit_colored_textured.adb
index b3a603f..ba683ee 100644
--- a/3-mid/opengl/source/lean/geometry/opengl-geometry-lit_colored_textured.adb
+++ b/3-mid/opengl/source/lean/geometry/opengl-geometry-lit_colored_textured.adb
@@ -99,8 +99,24 @@ is
          white_Texture       := openGL.Texture.Forge.to_Texture (white_Image);
          the_Program.Program := new openGL.Program.lit.item;
 
-         the_Program.  vertex_Shader.define (Shader.Vertex,   "assets/opengl/shader/lit_colored_textured.vert");
-         the_Program.fragment_Shader.define (Shader.Fragment, use_fragment_Shader);
+         the_Program.vertex_Shader.define (Shader.Vertex, "assets/opengl/shader/lit_colored_textured.vert");
+
+         if use_fragment_Shader = "assets/opengl/shader/lit_colored_text.frag"
+         then
+            the_Program.fragment_Shader.define (Shader.Fragment, use_fragment_Shader);
+
+            -- TODO: The below code produces ugly text. Investigate and fix.
+            --
+            --  the_Program.fragment_Shader.define (Shader.Fragment, (asset_Names' (1 => to_Asset ("assets/opengl/shader/version.header"),
+            --                                                                      2 => to_Asset ("assets/opengl/shader/texturing-frag.snippet"),
+            --                                                                      3 => to_Asset ("assets/opengl/shader/lighting-frag.snippet"),
+            --                                                                      4 => to_Asset ("assets/opengl/shader/lit_colored_textured.frag"))));
+         else
+            the_Program.fragment_Shader.define (Shader.Fragment, (asset_Names' (1 => to_Asset ("assets/opengl/shader/version.header"),
+                                                                                2 => to_Asset ("assets/opengl/shader/texturing-frag.snippet"),
+                                                                                3 => to_Asset ("assets/opengl/shader/lighting-frag.snippet"),
+                                                                                4 => to_Asset ("assets/opengl/shader/lit_colored_textured.frag"))));
+         end if;
 
          the_Program.Program.define (the_Program.  vertex_Shader'Access,
                                      the_Program.fragment_Shader'Access);
diff --git a/3-mid/opengl/source/lean/geometry/opengl-geometry-lit_colored_textured_skinned.adb b/3-mid/opengl/source/lean/geometry/opengl-geometry-lit_colored_textured_skinned.adb
index ce23aa2..4d5b3de 100644
--- a/3-mid/opengl/source/lean/geometry/opengl-geometry-lit_colored_textured_skinned.adb
+++ b/3-mid/opengl/source/lean/geometry/opengl-geometry-lit_colored_textured_skinned.adb
@@ -126,7 +126,11 @@ is
       white_Texture := openGL.Texture.Forge.to_Texture (white_Image);
 
       vertex_Shader  .define (Shader.Vertex,   "assets/opengl/shader/lit_colored_textured_skinned.vert");
-      fragment_Shader.define (Shader.Fragment, "assets/opengl/shader/lit_colored_textured_skinned.frag");
+      fragment_Shader.define (Shader.Fragment, (asset_Names' (1 => to_Asset ("assets/opengl/shader/version.header"),
+                                                              2 => to_Asset ("assets/opengl/shader/lighting-frag.snippet"),
+                                                              3 => to_Asset ("assets/opengl/shader/texturing-frag.snippet"),
+                                                              4 => to_Asset ("assets/opengl/shader/lit_colored_textured.frag"))));
+      --  fragment_Shader.define (Shader.Fragment, "assets/opengl/shader/lit_colored_textured_skinned.frag");
 
       the_Program.define (  vertex_Shader'Access,
                           fragment_Shader'Access);
diff --git a/3-mid/opengl/source/lean/geometry/opengl-geometry-lit_textured.adb b/3-mid/opengl/source/lean/geometry/opengl-geometry-lit_textured.adb
index f1f1714..1ad1a9c 100644
--- a/3-mid/opengl/source/lean/geometry/opengl-geometry-lit_textured.adb
+++ b/3-mid/opengl/source/lean/geometry/opengl-geometry-lit_textured.adb
@@ -82,8 +82,9 @@ is
 
       vertex_Shader  .define (Shader.Vertex,   "assets/opengl/shader/lit_textured.vert");
       fragment_Shader.define (Shader.Fragment, (asset_Names' (1 => to_Asset ("assets/opengl/shader/version.header"),
-                                                              2 => to_Asset ("assets/opengl/shader/texturing.frag"),
-                                                              3 => to_Asset ("assets/opengl/shader/lit_textured.frag"))));
+                                                              2 => to_Asset ("assets/opengl/shader/texturing-frag.snippet"),
+                                                              3 => to_Asset ("assets/opengl/shader/lighting-frag.snippet"),
+                                                              4 => to_Asset ("assets/opengl/shader/lit_textured.frag"))));
       the_Program := new openGL.Program.lit.item;
       the_Program.define (  vertex_Shader'Access,
                             fragment_Shader'Access);
diff --git a/3-mid/opengl/source/lean/geometry/opengl-geometry-lit_textured_skinned.adb b/3-mid/opengl/source/lean/geometry/opengl-geometry-lit_textured_skinned.adb
index fc29b21..678f887 100644
--- a/3-mid/opengl/source/lean/geometry/opengl-geometry-lit_textured_skinned.adb
+++ b/3-mid/opengl/source/lean/geometry/opengl-geometry-lit_textured_skinned.adb
@@ -115,8 +115,11 @@ is
       white_Texture := openGL.Texture.Forge.to_Texture (white_Image);
 
       vertex_Shader  .define (Shader.Vertex,   "assets/opengl/shader/lit_textured_skinned.vert");
-      fragment_Shader.define (Shader.Fragment, "assets/opengl/shader/lit_textured_skinned.frag");
-
+      --  fragment_Shader.define (Shader.Fragment, "assets/opengl/shader/lit_textured_skinned.frag");
+      fragment_Shader.define (Shader.Fragment, (asset_Names' (1 => to_Asset ("assets/opengl/shader/version.header"),
+                                                              2 => to_Asset ("assets/opengl/shader/lighting-frag.snippet"),
+                                                              3 => to_Asset ("assets/opengl/shader/texturing-frag.snippet"),
+                                                              4 => to_Asset ("assets/opengl/shader/lit_textured.frag"))));
       the_Program.define (  vertex_Shader'Access,
                           fragment_Shader'Access);
       the_Program.enable;
diff --git a/3-mid/opengl/source/lean/geometry/opengl-geometry-textured.adb b/3-mid/opengl/source/lean/geometry/opengl-geometry-textured.adb
index f7f2b9a..31f74a9 100644
--- a/3-mid/opengl/source/lean/geometry/opengl-geometry-textured.adb
+++ b/3-mid/opengl/source/lean/geometry/opengl-geometry-textured.adb
@@ -76,7 +76,7 @@ is
 
             vertex_Shader  .define (Shader.vertex,   "assets/opengl/shader/textured.vert");
             fragment_Shader.define (Shader.Fragment, (asset_Names' (1 => to_Asset ("assets/opengl/shader/version.header"),
-                                                                    2 => to_Asset ("assets/opengl/shader/texturing.frag"),
+                                                                    2 => to_Asset ("assets/opengl/shader/texturing-frag.snippet"),
                                                                     3 => to_Asset ("assets/opengl/shader/textured.frag"))));
             the_Program := new openGL.Program.item;
 
diff --git a/3-mid/opengl/source/lean/model/opengl-model-texturing.adb b/3-mid/opengl/source/lean/model/opengl-model-texturing.adb
new file mode 100644
index 0000000..9150bba
--- /dev/null
+++ b/3-mid/opengl/source/lean/model/opengl-model-texturing.adb
@@ -0,0 +1,202 @@
+with
+     openGL.Model,
+     GL.lean,
+     GL.Binding,
+     ada.Strings.fixed;
+
+with ada.Text_IO;
+
+
+package body openGL.Model.texturing
+is
+   use GL;
+
+
+   type texture_Units is array (texture_Set.texture_Id) of GLenum;
+
+   all_texture_Units : constant texture_Units := (GL_TEXTURE0,
+                                                  GL_TEXTURE1,
+                                                  GL_TEXTURE2,
+                                                  GL_TEXTURE3,
+                                                  GL_TEXTURE4,
+                                                  GL_TEXTURE5,
+                                                  GL_TEXTURE6,
+                                                  GL_TEXTURE7,
+                                                  GL_TEXTURE8,
+                                                  GL_TEXTURE9,
+                                                  GL_TEXTURE10,
+                                                  GL_TEXTURE11,
+                                                  GL_TEXTURE12,
+                                                  GL_TEXTURE13,
+                                                  GL_TEXTURE14,
+                                                  GL_TEXTURE15,
+                                                  GL_TEXTURE16,
+                                                  GL_TEXTURE17,
+                                                  GL_TEXTURE18,
+                                                  GL_TEXTURE19,
+                                                  GL_TEXTURE20,
+                                                  GL_TEXTURE21,
+                                                  GL_TEXTURE22,
+                                                  GL_TEXTURE23,
+                                                  GL_TEXTURE24,
+                                                  GL_TEXTURE25,
+                                                  GL_TEXTURE26,
+                                                  GL_TEXTURE27,
+                                                  GL_TEXTURE28,
+                                                  GL_TEXTURE29,
+                                                  GL_TEXTURE30,
+                                                  GL_TEXTURE31);
+
+
+
+
+   procedure enable (for_Model   : in openGL.Model.view;
+                     Uniforms    : in texturing.Uniforms;
+                     texture_Set : in openGL.texture_Set.Item)
+   is
+      use GL.Binding,
+          GL.lean;
+
+      use type GLint;
+
+   begin
+      for i in 1 .. openGL.texture_Set.texture_Id (for_Model.texture_Count)
+      loop
+         Uniforms.Textures (i).fade_Uniform.Value_is (Real (for_Model.Fade (i)));
+
+         glUniform1i     (Uniforms.Textures (i).texture_Uniform.gl_Variable,
+                          GLint (i) - 1);
+         glActiveTexture (all_texture_Units (i));
+         glBindTexture   (GL_TEXTURE_2D,
+                          texture_Set.Textures (i).Object.Name);
+      end loop;
+
+      Uniforms.Count.Value_is (for_Model.texture_Count);
+   end enable;
+
+
+
+
+   procedure create (Uniforms    :    out texturing.Uniforms;
+                     for_Program : in     openGL.Program.view)
+   is
+   begin
+      for Id in texture_Set.texture_Id'Range
+      loop
+         declare
+            use ada.Strings,
+                ada.Strings.fixed;
+            i                    : constant Positive := Positive (Id);
+            texture_uniform_Name : constant String   := "Textures[" & trim (Natural'Image (i - 1), Left) & "]";
+            fade_uniform_Name    : constant String   := "Fade["     & trim (Natural'Image (i - 1), Left) & "]";
+         begin
+            Uniforms.Textures (Id).texture_Uniform := for_Program.uniform_Variable (named => texture_uniform_Name);
+            Uniforms.Textures (Id).   fade_Uniform := for_Program.uniform_Variable (named =>    fade_uniform_Name);
+         end;
+      end loop;
+
+
+      Uniforms.Count := for_Program.uniform_Variable ("texture_Count");
+   end create;
+
+
+
+
+   -------------
+   --- Mixin ---
+   -------------
+
+   --  generic
+   package body Mixin
+   is
+      use openGL.texture_Set;
+
+
+      texture_Uniforms : texturing.Uniforms;
+
+      procedure create_Uniforms (for_Program : in openGL.Program.view)
+      is
+      begin
+         create (texture_Uniforms, for_Program);
+      end create_Uniforms;
+
+
+
+      overriding
+      procedure Fade_is (Self : in out Item;   Now   : in texture_Set.fade_Level;
+                                               Which : in texture_Set.texture_ID := 1)
+      is
+      begin
+         Self.texture_Set.Textures (which).Fade := Now;
+      end Fade_is;
+
+
+
+      overriding
+      function Fade (Self : in Item;   Which : in texture_Set.texture_ID := 1) return texture_Set.fade_Level
+      is
+      begin
+         return Self.texture_Set.Textures (which).Fade;
+      end Fade;
+
+
+
+      overriding
+      procedure Texture_is (Self : in out Item;   Now   : in openGL.Texture.Object;
+                                                  Which : in texture_Set.texture_ID := 1)
+      is
+      begin
+         Texture_is (in_Set => Self.texture_Set,
+                     Which  => Which,
+                     Now    => Now);
+      end Texture_is;
+
+
+
+      overriding
+      function Texture (Self : in Item;   Which : texture_Set.texture_ID := 1) return openGL.Texture.Object
+      is
+      begin
+         return openGL.texture_Set.Texture (in_Set => Self.texture_Set,
+                                            Which  => Which);
+      end Texture;
+
+
+
+      --  overriding
+      --  procedure Texture_is (Self : in out Item;   Now : in openGL.Texture.Object)
+      --  is
+      --  begin
+      --     Texture_is (in_Set => Self.texture_Set,
+      --                 Now    => Now);
+      --  end Texture_is;
+      --
+      --
+      --
+      --  overriding
+      --  function Texture (Self : in Item) return openGL.Texture.Object
+      --  is
+      --  begin
+      --     return texture_Set.Texture (in_Set => Self.texture_Set,
+      --                                 Which  => 1);
+      --  end Texture;
+
+
+
+      overriding
+      procedure enable_Textures (Self : in out Item)
+      is
+      begin
+         --  ada.Text_IO.put_Line (Self.Model'Image);
+
+         texturing.enable (for_Model   => Self.Model.all'Access,
+                           Uniforms    => texture_Uniforms,
+                           texture_Set => Self.texture_Set);
+      end enable_Textures;
+
+
+   end Mixin;
+
+
+
+end openGL.Model.texturing;
diff --git a/3-mid/opengl/source/lean/model/opengl-model-texturing.ads b/3-mid/opengl/source/lean/model/opengl-model-texturing.ads
new file mode 100644
index 0000000..fc7cd55
--- /dev/null
+++ b/3-mid/opengl/source/lean/model/opengl-model-texturing.ads
@@ -0,0 +1,103 @@
+with
+     openGL.Variable.uniform,
+     openGL.texture_Set,
+     openGL.Program;
+
+limited
+with
+     openGL.Model;
+
+
+private
+package openGL.Model.texturing
+--
+-- Provides texturing support for models.
+--
+is
+
+   --- Uniforms
+   --
+
+   type texture_fade_Uniform_pair is
+      record
+         texture_Uniform : openGL.Variable.uniform.sampler2D;
+         fade_Uniform    : openGL.Variable.uniform.float;
+      end record;
+
+
+   type texture_fade_Uniform_pairs is array (openGL.texture_Set.texture_Id
+                                             range 1 .. openGL.texture_Set.max_Textures) of texture_fade_Uniform_pair;
+
+   type Uniforms is
+      record
+         Textures : texture_fade_Uniform_pairs;
+         Count    : openGL.Variable.uniform.int;
+      end record;
+
+
+
+   --- Operations
+   --
+
+   procedure enable (for_Model   : in     openGL.Model.view;
+                     Uniforms    : in     texturing.Uniforms;
+                     texture_Set : in     openGL.texture_Set.Item);
+
+
+
+   procedure create (Uniforms    :    out texturing.Uniforms;
+                     for_Program : in     openGL.Program.view);
+
+
+
+
+   -------------
+   --- Mixin ---
+   -------------
+
+   generic
+   package Mixin
+   is
+      type Item is new Geometry.item with private;
+
+
+      procedure create_Uniforms (for_Program : in     openGL.Program.view);
+
+
+
+      overriding
+      procedure Fade_is      (Self : in out Item;   Now   : in texture_Set.fade_Level;
+                                                    Which : in texture_Set.texture_ID := 1);
+      overriding
+      function  Fade         (Self : in     Item;   Which : texture_Set.texture_ID := 1) return texture_Set.fade_Level;
+
+
+      overriding
+      procedure Texture_is   (Self : in out Item;   Now   : in openGL.Texture.Object;
+                                                    Which : in texture_Set.texture_ID := 1);
+      overriding
+      function  Texture      (Self : in     Item;   Which : in texture_Set.texture_ID := 1) return openGL.Texture.Object;
+
+      --  overriding
+      --  procedure Texture_is   (Self : in out Item;   Now : in openGL.Texture.Object);
+      --
+      --  overriding
+      --  function  Texture      (Self : in     Item)     return openGL.Texture.Object;
+
+
+      overriding
+      procedure enable_Textures (Self : in out Item);
+
+
+   private
+
+      type Item is new Geometry.item with
+         record
+            texture_Set : openGL.texture_Set.item;
+         end record;
+
+   end Mixin;
+
+
+
+end openGL.Model.texturing;