Stone Design/Stone Design.iso/Stone_Friends/Wave/WavesWorld/Documentation/WW3DKit/stuff/README

Text File | 1995-03-22 | 3.4 KB | 69 lines

send mail to [e-mail] with any questions.

Thi directory contains the source for my 3DKit.  This version is based
on top of NeXT's, but it's been designed to port to OpenGL and Tk.
Hence, it's a bit different than your normal NeXT-like kit.

From a UI perspective, there's only one object of interest: the
WW3DWell.  The idea behind the WW3DWell is to encapsulate the
functionality you would want when integrating 3D into an arbitrary
app.  It should support photorealistic rendering, direct manipulation,
browsing and inspecting of the parts of the shape hiearchy, drag and
drop, etc.  I think it works pretty well, but there are still parts
that aren't done.

From a programmer's perspective, the most obvious classes are
WW3DShape and the subclasses of RIBCommand.  One of my concerns in
designing this kit was trying to come up with a way to enumerate all
possible classes beforehand, so that users wouldn't need to subclass.
I have various nefarious reasons for this.  This is in direct contrast
to the N3DKit's style, wherein you subclass N3DShape to draw your
particular kind of geometry.  In my 3DKit, their is only one subclass
of N3DShape: WW3DShape.  a WW3DShape has a list of ribCommands, each
of which is a subclass of RIBCommand.  For each appropriate Ri*()
routine in the RenderMan interface, I've made a subclass of
RIBCommand, each of which knows how to do a set of things, like render
themselves and calculate their bounding box.  When you tell a
WW3DShape to render itself, it in turn just tells all of its
ribCommands to render themselves.  This is cool because you can parse
a rib file into this sort of shape hierarchy, interact with it, and
get the same rib file out the back end, including transformations.
This is pretty hard to do any other way.

The main coolness of this kit, though, is the fact that it offers the
programmer a complete time-based modeling language based on tcl, the
tool command language.  For more info on tcl, look in ../tcl/doc, read
the newsgroup comp.lang.tcl, ftp to sprite.berkeley.edu and pick up
the Postscript pre-print of the forthcoming tcl book from
Addison-Wesley.

Anyway, I've added a complete RenderMan binding to tcl, along with a
few interesting commands (the most interesting being EveCmd and
ApplyToCTM).  I haven't figured out the best way to document this yet,
so y'all should take a look at the code and let me know what's really
opaque.

This kit isn't finished yet, but I am interested in feedback.

More Info
---------
The real power of these two WavesWorld palettes can be seen when you
combine them to start building what I call "malleable media".  This is
really one of the ideas from my PhD, and it's one that I'm very
excited about.  The basic idea is this:

clip art is dead; it's static.  If someone gives you a piece of 2D
clip art as an EPS, the best you can do is toss it in your
illustration; maybe you can scale it or rotate it, but that's about
it.  What you really want is the Virtuoso/Illustrator/Create file, so
you can interact with it.

In the same way, a RIB file is pretty dead.  You can extract shape
hierarchy info from it, but what you really want is a modeling
language, with variables, looping constructs, procedures and dynamic
constraints.  Assuming you design a modeling language, you then want
to write your clip objects in it.  You obviously want it to reduce
itself to RIB eventually, but you want to be able to easily attach UI
elements to manipulate variables inside a model program before it gets
reduced to RIB.