RFC 2077 (rfc2077) - Page 3 of 13
The Model Primary Content Type for Multipurpose Internet Mail Extensions
Alternative Format: Original Text Document
RFC 2077 Model Primary MIME Types January 1997
temporal units. This allows for differing elements to be combined
non-arbitrarily.
4. Models can be single objects or composed of a collection of
objects. These normally independent objects are arranged
in a master/slave scenario so that one object acts as the
reference, or primary object, which defines how the other
objects interrelate and behave. This allows for the creation
of mathematical, physical, economic, behavioral, etc. models
which typically are composed of different elements. The key is
in the description: these types describe how something
"behaves"; contrasted to typical data types which describe
how something "is".
The inclusion of this "collective" system works similar to the
Email system's multipart/related type which defines the actions
of the individual parts. Further specification of the model/*
subtypes utilizing these properties is left to the subtype
authors.
With these assumptions:
a. the default dimensionality will be spatial and temporal (but
any are allowed).
b. it is presumed that models will contain underlying structure
which may or may not be immediately available to the
user. (fluid dynamics vector fields, electromagnetic
propagation, interrelated IGES dimensional specifiers, VRML
materials and operators, etc.)
c. it is assumed that basis set conversion between model domains
is lossless. The interpretation of the data may change but
the specification will not. i.e. convert the model of the
U.S.A. Gross Domestic Product into a VRML model and navigate
it to explore the variances and interrelationships. The model
has many dimensions but also "passages" and "corridors"
linking different parts of it. A similar situation is true
for meshes and CAD files. The key is identifying the basis set
conversion which makes sense.
d. models are grouped to assure LESS loss of information between
the model subtypes than to subtypes of other primary
types. (i.e. converting a chemical model into an image is
more lossy than concerting it into a VRML model).
Nelson, et. al. Standards Track