Texture and Reflection in Computer Generated Images
In 1974 Catmull developed a new algorithm
for rendering images of bivariate surface patches. 
 This paper describes extensions of this algorithm in
the areas of texture simulation and lighting models. 
 The parameterization of a patch defines a coordinate
system which is used as a key for mapping patterns 
onto the surface.  The intensity of the pattern at each
picture element is computed as a weighted average 
of regions of the pattern definition function. The shape
and size of this weighting function are chosen 
using digital signal processing theory.  The patch rendering
algorithm allows accurate computation of 
the surface normal to the patch at each picture element,
permitting the simulation of the mirror reflections. 
 The amount of light coming from a given direction is
modeled in a similar manner to the texture mapping 
and then added to the intensity obtained from the texture
mapping.  Several examples of images synthesized 
using these new techniques are included.
CACM October, 1976
Blinn, J. F.
Newell, M. E.
