doh! fragment-shader war rot zu testzwecken -.-

shaders/fragment.shader

@@ -8,5 +8,5 @@ out vec4 fg_FragColor;
 void main(void)
 {
 //copy-shader
-   fg_FragColor = vec4(1,0,0,1) + 0.01* fg_SmoothColor;
+   fg_FragColor = fg_SmoothColor;
 }

shaders/vertex.shader

@@ -11,7 +11,7 @@ in vec3 fg_VertexIn;
 in vec3 fg_NormalIn;
 
 //output-data for later stages
-out vec4 fg_SmoothColor;
+smooth out vec4 fg_SmoothColor;
 
 void main()
 {