how to make it more realistic

have a database of surfaces for different types of objects
  blemishes, marks
  scratches, scuffs,
  imperfections,
  organic artifacts
same for minute 3d textures of surfaces

emulate physics of flesh, bone and skin, as three different layers.
  actually skin might need 2-3 layers.
  flesh could just be one jelatinous substance governed my the laws of gelatiny.
  chest cavity and ribs for breathing

have joints in appropriate places.
flesh attaches to the bones
skin attaches to the flesh

simulate movement
   know where the joints are
   balance the mass of the animal, simulate regular gravity
   simulate the action of a limited set of muscles with its smoothness and rhythmic motions
   coordinate the motion on a higher level of command, let the system do the rest.
   or have people animate it with bioposiitioning and adapt

develop a mathematics for the physics of hair (not individual follicles), like fluid dynamics, render the motions but add in the surface texture of hair, stray hairs, and opacity where the hair is thin but not close enough to see individual hairs
^^ probably been done since i wrote this idea a long time ago

need lots of mouth muscles, especially for talking. analyze the sound and know what movements are being made.
also smiling and other emotions need lots of muscles and nkowledge of how they're contorted.

clothes must have the proper physics. it's more rigid than silk. and wind is a factor.

functions for randomizing information about certain kinds of surfaces within realistic probability curves but within the parameters specified by the artists.
skin textures
faces and eyes
visible muscle shapes
hair lines
hair fullness, thickness, and color
etc.
have a way for artists to define shapes (like faces) but showing the improbability of each dimension as it's affected.

simulate abstract mechanics of the motor neurology ?

develop dimensions of personology to help parameterize habitual ways of moving for a character