[update] Replaced MatrixFactory with ModelMatrixFactory came from gl4d.

src/sj/LobbyWorld.d

@@ -45,7 +45,7 @@ class LobbyWorld {
   ///
   mat4 view = mat4.look_at(vec3(0, 0, -1), vec3(0, 0, 0), vec3(0, 1, 0));
   ///
-  vec3 light_color = vec3(1, 1, 1, 1);
+  vec3 light_color = vec3(1, 1, 1);
   ///
   vec3 light_direction = vec3(0, 1, 0);
   ///