public AnimatedModelEntity(Model model)
{
this.model = model;
this.size = Vector3.One;
this.speed = 0.1f;
skinning_data = model.Tag as SkinningData;
if (skinning_data == null)
throw new InvalidOperationException
("This model does not contain a SkinningData tag.");
animation_player = new AnimationPlayer(skinning_data);
StartDefaultClip();
}