GFX Sensations 1/Graphic Sensations - Volume 1.iso/tools/amiga/3d_tools/rend10.lzh/REND1.0/AMIGA_VR_TOOLKIT_NOTICE

Text File | 1994-02-28 | 10.5 KB | 238 lines

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                   AMIGA VR TOOLKIT

                  Pre-Release Notice

                   February 7, 1994

   A complex, flexible, and extremely powerful set of tools that will provide
             the basis for public domain VR software for the AMIGA.

        written by  Michael P. Schenck  [e-mail]

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    The AMIGA VR Toolkit is a library of classes and functions that
integrate to provide a complete set of tools for constructing, visualizing
and interacting with virtual environments.  The toolkit takes the form
of an SAS/C 6.5 C++ linkable library.

    The toolkit is in development and is heading toward its
first release.  A brief summary of the features that will be contained in the
toolkit are described below.  Some of these have already been developed
while others are still in the design stage.  Much of the initial theory behind
the functionality of the toolkit is complete.  There are alot of details to be
worked out and choices to be made.  If you are interested in having a hand in
the final design of the toolkit, read the summary and follow the instructions
at the end.


ENVIRONMENT CONSTRUCTION AND CONTROL
------------------------------------

    PRIMITIVES

     A Primitive class allows primitives to be defined and used
     in Objects.  Control all aspects of a primitive such as points,
     polygons, colors of the polygons, and eventually things like
     textures and transparencies.

    TRANSFORMATIONS

     The Transformation class which is used to create the transformation
     objects within the Control Classes contains a variety of standard
     transformations, but can also be customized.  Some of the standard
     ones will be all the rotations, translations, scalings, shears, and
     deformations.  To set the transformation to a rotation, just specify
     the angle or angles.  It's that simple.  Setting your own customized
     Matrix is just as easy.

    CONTROLS

     Objects are controlled through the use of Control classes which add
     control points and govern the movement and design of the Object.
     There are standard and custom Control classes.  Some examples
     of standard ones are Hinge and Pivot.  Control classes can be made
     by combining Transformation objects and other standard and custom
     "governing" classes which help to control the manipulation of the
     Transformations.  These "governing" classes could include classes
     for input such as a PowerGlove class or they could be Physical
     Model based classes or Artificial Intelligence based classes.

    OBJECTS

     An Object class is comprised of Primitives and different Control
     classes that link together to make up and control the Object.
     Objects can be added and removed from different Worlds.  They can be
     activated or deactivated which makes them a portion of the environment
     or not.  Objects are the representation of the Entity that controls
     them.  Simply, they represent the "bodies" of the Entities.

    WORLDS

            A World class groups Objects into a single environment which can be
     handled individually.  Therefore, multiple worlds can be defined
     and all rendered at once or individually.

    ENTITIES

     Entities represent the "soul" or the "essence" of an Object.  Objects
     are just controllable bodies that exist in the environment.  Entities
     give them thier function and thier "intelligence".  Entities are not
     specific classes or functions, but a hierarchy of custom classes and
     functions within the application the toolkit is linked too.  These
     classes and functions are used to construct, initialize, and control
     the Entity's Object within the environment.  They can be comprised of
     logic and control routines or they could simply be a conduit for
     information that is being sent to the Object's Control and Primitive
     objects.  Entities can be built up of subclasses that each contain
     a Primitive or Primitives and Control objects which comprise a
     "portion" of the entire Entity.  These subclasses provide the
     "essence" for a single portion of the Entity and can be duplicated
     just like copying a variable.  For example, you could create a virtual
     robot spider where each leg would be a different object of the same
     subclass and they all would be controlled from a single body object!


ENVIRONMENT VISUALIZATION AND RESPONSE
--------------------------------------

    RENDERING ENGINE

     At the heart of the toolkit is a pipelined rendering engine.  The
     pipeline will consist of two stages.  The first stage will be handled
     by the CPU and will consist of updating any changes in any of the
     Worlds (converting primitive coords to world coords via a map of
     transformations for each changed object or portion of changed object
     in each world), detecting collisions and reporting them to objects,
     and creating a raster list of all polygons inside the view volume for
     each Viewpoint.  The second stage is handled by the blitter.  It will
     be fed the raster list by the CPU in the form of a continuous stream
     of blits.  While the blitter is working, the CPU will be back to the
     first stage of the pipeline working on the next frame (if any updates
     or changes have occured in the environment).  The overhead in
     switching processes (to feed the blitter more raster ops) will be
     minimal compared to the speed gained by having a pipeline.  This will
     be especially true where the processor way outperforms the blitter.
     Even if the CPU is fast, the blitter of course still governs the frame
     rate due to its speed.  Therefore, the maximum frame rate will be
     much slower in machines with a slower blitter.  The difference between
     AGA and ECS or OCS machines will be significant.  Just as the
     difference between AGA and AAA (if it ever comes out) will also be
     significant.  The optimum frame rate will be obtained where the time
     to process a frame is approximately equivalent to the time to draw the
     previous frame.  This equality is governed by the CPU speed, the
     overall blitter performance (clock rate and bandwidth which is
     dependent on the amount of DMA available to it), and the scene
     complexity from frame to frame.

    GRAPHICS MODES

     The graphics supported by the rendering engine are wireframe and
     solid shaded polygons.  In the shaded polygon mode, special effects
     may be added such as textures or transparency.  These of course will
     come at a later date, but will be figured into the initial design.
     Hidden surface removal is in the form of a painters algorithm
     which will probably be modified.  This is to maintain a decent frame
     rate and to remove most visual artifacts from the scene.

    LIGHTING

     Lighting is simple.  Primarily ambient light and a single light
     vector.  This may get more complicated later.

    COLLISION DETECTION

    -Collision in the environment is optional, but designed in.  This
     is due to the large amount of extra computation it requires.


SYSTEM CONTROL AND INTERFACING
------------------------------

    VIEWPORTS AND VIEWPOINTS

     Viewport and Viewpoint classes provide multiple and simultaneous views
     into one or more environments.  You can look at the same or different
     worlds at the same time and from different positions.

    TEXT AND GRAPHICS

     Support for Text and Graphics through the Viewports.  These are in
     the form of various functions and classes.

    SIMULATION TIMING

     A Timer class provides all the simulation timing required.

    SOUND AND MUSIC

     Classes for sound and music which can be used in an Entity or
     Control class.  This will come later, not a high priority.

    I/O INTERFACE

     Classes for linking I/O to Objects are in the form of Control
     classes.  These use basic I/O classes and functions combined
     with Transformation objects to directly map input from the user to
     the control point represented by the Transformation object(s). All the
     systems resources such as serial ports, parallel ports, the keyboard
     and the mouse will all be available through functions or classes
     provided by the toolkit.

    COMPUTATION

     The core of the computation performed by the toolkit will be performed
     in fixed point integer math, but it will seem from a an application
     stand point that the toolkit uses floating point math.  This is to allow
     applications to gain from using simplistic and accurate floating point
     while the toolkit itself works in a tricker form of fixed point integer
     math.  Inputs into the toolkit (in floating point values) will have
     to be limited in size.  This means that there will be a maximum
     and minimum value imposed on the actual value of the numbers passed
     in.  This will probably not cause a problem in nearly all situations.


BENIFITS, PROBLEMS, AND PLANS

    The design for this toolkit is very strong in the creation and
control of complex environments.  This is where it shines and is by far
the most important part.  But having a complex environment rendered at 2
frames a second isn't so good.  In my attempt to make this an extremly
powerful toolkit for AMIGA VR, I am also attempting to design a powerful
enough rendering engine to back it up.  This requires alot of optimization,
tricks, and understanding to develop a fast rendering engine.  We do have
the blitter to aid us, but it isn't the end all of aids for rendering!
This toolkit, over time, will probably reflect the best effort possible
to use the blitter for rendering complex 3D environments in conjuction
with the CPU!  I am personally looking forward to AAA's increase in blitter
speed which when combined with a 68060 or RISC CPU could give this toolkit
that sharp edge provided by a robust frame rate!

    I am happy to say that this software will all be free.  I only ask that
you participate in its development.  It could very well become the best
PD VR Toolkit around with a little work!  So...

    IF YOU ARE INTERESTED IN THE DEVELOPMENTS OF THIS TOOLKIT AS IT
    WORKS ITS WAY TO THE FIRST RELEASE AND WANT TO EXPRESS YOUR
    IDEAS AND/OR CONCERNS ABOUT THE DESIGN OF THE TOOLKIT OR JUST
    WANT TO BE KEPT INFORMED OF ITS PROGRESS, SEND ME AN EMAIL MESSAGE
    STATING SO AND I WILL PUT YOU ON A MAILING LIST AND KEEP YOU
    UPDATED.  I AM LOOKING FOR INPUT IN THE DESIGN PROCESS BECAUSE
    THIS IS BY FAR THE MOST IMPORTANT PART.  I WANT YOUR THOUGHTS,
    CONCERNS, AND CRITICISMS!


              Send email to...

                Michael P. Schenck

                        at

             [e-mail]


     THANK YOU IN ADVANCE FOR YOUR INTEREST AND EFFORT