+void Light::update_matrix()
+{
+ Vector3 up_dir;
+ if(20*abs(direction.z)>abs(direction.x)+abs(direction.y))
+ up_dir.y = 1;
+ else
+ up_dir.z = 1;
+ Vector3 right_dir = normalize(cross(direction, up_dir));
+
+ Vector4 columns[4];
+ columns[0] = compose(right_dir, 0.0f);
+ columns[1] = compose(cross(right_dir, direction), 0.0f);
+ columns[2] = compose(-direction, 0.0f);
+ columns[3] = position;
+ matrix = Matrix::from_columns(columns);
+}
+