Исправление шейдера для работы с нормалями

lab2/res/cube.mtl

@@ -1,12 +1,12 @@
 # Blender MTL File: 'cube.blend'
 # Material Count: 1
 
-newmtl Material
+newmtl CubeColor
 Ns 250.000000
 Ka 1.000000 1.000000 1.000000
-Kd 0.800000 0.800000 0.800000
+Kd 0.800000 0.447721 0.037177
 Ks 0.500000 0.500000 0.500000
 Ke 0.000000 0.000000 0.000000
-Ni 1.000000
+Ni 1.450000
 d 1.000000
 illum 2

lab2/res/cube.obj

@@ -16,7 +16,7 @@ vn -1.0000 0.0000 0.0000
 vn 0.0000 -1.0000 0.0000
 vn 1.0000 0.0000 0.0000
 vn 0.0000 0.0000 -1.0000
-usemtl Material
+usemtl CubeColor
 s off
 f 5//1 3//1 1//1
 f 3//2 8//2 4//2

lab2/res/main.vsh

@@ -5,10 +5,18 @@ layout (location = 1) in vec3 v_normal;
 
 out vec4 a_color;
 uniform mat4 projview;
+uniform mat4 model;
 
 void main(){
 //	gl_Position = vec4(v_position, 1) * projview;
-	gl_Position = projview * vec4(v_position, 1);
-	a_color = vec4(0.5, 0, 1, 1);
+	gl_Position = projview * model * vec4(v_position, 1);
+
+	// dot получается [-1 ... 1]
+	float l = dot((model * vec4(v_position, 1)).xyz, normalize(vec3(1, 1, 1)));
+	// сначала делаем диапазон [1 ... 3]
+	// потом [0.5 ... 1]
+	l = (l + 2) / 3;
+
+	a_color = vec4(vec3(0.5, 0, 1) * l, 1);
 }