Facial Animation Techniques

Facial Animation Techniques

Mr. K. Gnanamuthu Prakash Dr. S. Balasubramanian
Research Scholar Research Supervisor
Anna University Coimbatore Anna University Coimbatore
Coimbatore Coimbatore

Abstract

A major unsolved problem in computer graphics is the construction and animation of realistic human facial models. Traditionally, facial models have been built painstakingly by manual digitization and animated by ad hoc parametrically controlled facial mesh deformations or kinematic approximation of muscle actions. Fortunately, animators are now able to digitize facial geometries through the use of scanning range sensors and animate them through the dynamic
simulation of facial tissues and muscles. However, these techniques require considerable user input to construct facial models of individuals suitable for animation.

Facial Modeling Techniques

Polygonal – Polygonal modeling specifies exactly each 3d point, which connected to each other as polygons. This is an exacting way to get topology (points) where you need it on a face and not where you don’t.
Advantages: Specific control and placement (of topology and mapping).
Disadvantages: Hard to work with polygon data as you must work with it directly.

Patches (NURBs) Patches (or a set of splines) indirectly defines a smooth curve surface from a set of control points. A small amount of control points (called CVs in Maya) can define a complex surface. One type of spline is called NURBs which stands for Non-Uniform Rational B-Splines. This type of batch allows each control point to have its own weight that can affect the “pinch” of the curve at the point. So they are considered the most versatile of batches. They work very well for organic smooth objects so hence they are well suited for facial modeling however several issues arise.
Disadvantages:
To create a face from NURBS you must use topology (control points) evenly across the face but the face tends to have areas of high detail... [continues]

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