Image warping and morphing are useful in creating facial animations because the movements can be very smooth and have seamless transitions from one state, or position to another. Control points, such as muscle-based models, or underlying mesh models or images, such as texture maps may be warped and morphed. Warping is the distortion method which distorts and changes an image. Using one face as the starting face and another as the target face, one may change facial expression through the use of control lines on both faces. This is more commonly used for facial models than morphing. A good example of warping is . Morphing is also known as the transition morphing method; one object is actually changed into another object. Morphing is a combination of warping, tweening and dissolving algorithms.