bugfix: re-normalised normals in frag shaders

08_phong/test_fs.glsl

@@ -22,26 +22,29 @@ void main () {
 	// ambient intensity
 	vec3 Ia = La * Ka;
 
+	// normalize in case interpolation has upset normals' lengths
+	vec3 n_eye = normalize( normal_eye );
+
 	// diffuse intensity
 	// raise light position to eye space
 	vec3 light_position_eye = vec3 (view_mat * vec4 (light_position_world, 1.0));
 	vec3 distance_to_light_eye = light_position_eye - position_eye;
 	vec3 direction_to_light_eye = normalize (distance_to_light_eye);
-	float dot_prod = dot (direction_to_light_eye, normal_eye);
+	float dot_prod = dot (direction_to_light_eye, n_eye);
 	dot_prod = max (dot_prod, 0.0);
 	vec3 Id = Ld * Kd * dot_prod; // final diffuse intensity
 
 	// specular intensity
 	vec3 surface_to_viewer_eye = normalize (-position_eye);
 
-	//vec3 reflection_eye = reflect (-direction_to_light_eye, normal_eye);
+	//vec3 reflection_eye = reflect (-direction_to_light_eye, n_eye);
 	//float dot_prod_specular = dot (reflection_eye, surface_to_viewer_eye);
 	//dot_prod_specular = max (dot_prod_specular, 0.0);
 	//float specular_factor = pow (dot_prod_specular, specular_exponent);
 
 	// blinn
 	vec3 half_way_eye = normalize (surface_to_viewer_eye + direction_to_light_eye);
-	float dot_prod_specular = max (dot (half_way_eye, normal_eye), 0.0);
+	float dot_prod_specular = max (dot (half_way_eye, n_eye), 0.0);
 	float specular_factor = pow (dot_prod_specular, specular_exponent);
 
 	vec3 Is = Ls * Ks * specular_factor; // final specular intensity

15_phongtextures/test_fs.glsl

@@ -34,19 +34,22 @@ float specular_exponent = 100.0; // specular 'power'
 void main() {
 	vec3 light_pos_eye = (view * vec4 (light_position_world, 1.0)).xyz;
 
+	// normalize in case interpolation has upset normals' lengths
+	vec3 n_eye = normalize( norm_eye );
+
 	vec3 Ka = texture (ambient_map, st).rgb;
 	vec3 Ia = vec3 (0.2, 0.2, 0.2) * Ka;
 
 	vec4 texel = texture (diffuse_map, st);
 	vec3 Kd = texel.rgb;
 	vec3 surface_to_light_eye = normalize (light_pos_eye - pos_eye);
-	float dp = max (0.0, dot (norm_eye, surface_to_light_eye));
+	float dp = max (0.0, dot (n_eye, surface_to_light_eye));
 	vec3 Id = Kd * Ld * dp; 
 
 	vec3 Ks = texture (specular_map, st).rgb;
 	vec3 surface_to_viewer_eye = normalize (-pos_eye);
 	vec3 half_way_eye = normalize (surface_to_viewer_eye + surface_to_light_eye);
-	float dot_prod_specular = max (dot (half_way_eye, norm_eye), 0.0);
+	float dot_prod_specular = max (dot (half_way_eye, n_eye), 0.0);
 	float specular_factor = pow (dot_prod_specular, specular_exponent);
 	vec3 Is = Ls * Ks * specular_factor; // final specular intensity