And: Updatenormals is needed when a mesh is edited, eg. some vertices have been moved. The normals are then used by the lights, for shading and shininess etc.
Sometimes they are also pretty useful for you, eg. CollisionNX or PickedNX etc. if you want to calulate the angle an object has to bounce off a wall or something.
Sometimes they are also pretty useful for you, eg. CollisionNX or PickedNX etc. if you want to calulate the angle an object has to bounce off a wall or something.