Avarcron


   Table of Contents

	0. Introduction
	1. Avatar Guileline
	2. Background
	3. Design	
	4. Usage
	5. APIs




0. Introduction   Top

The department of computer science at New Mexico State University (NMSU) 
is developing a collaborative virtual enviroment (CVE) called Unicron for
distance learning puporse.  People who reside far from the school can 
still benefit in learning using Unicron.  They can use a personal computer 
to run a client program that would allow them to connect to the central
server running at NMSU.  Each user will use a graphical representation in 
Unicron, which represents the user.  This graphical representation in the
CVE is called avatar.  This project webpage describes our effor to design 
and develop such avatar.  We came up with a prototype avatar named Avarcron.
Avarcron is a humanoid avatar that has a head, a body, two arms, and two
legs.  Avarcron conforms to a simple guideline for all the avatar should
have in Unicron.  The guideline is discussed in the following section. And,
the detailed specification on Avarcron follows afterwards.


1. Avatar Guideline   Top

The guideline that all the avatar in Unicron should conform is simply a
class named, Avatar.  It is to be inherited by avatar models.

	class avarcron : Avatar (x1, x2, ..., xn)

The code section above says the class avarcron inherits the class Avatar.
The guideline the class Avatar would like to enforce is as follows.

	1. An avatar should have an avatar attribute files that contains
	   the following information on the avatar:
		
		a. name
		b. gender
		c. height
		d. xsize,ysize,zsize
		e. head shape
		f. skin color
		g. shirt color
		h. pants color
		i. shoes color
		j. snapshot picture of you.

	2. Follow the format of the avatar attribute file with a file
	   extension .avt.

That's it.  What the guideline does is to have each avatar store its
attributes in a file.  This eases re-creation of avatars.  To see the
format of an avatar attribute file, please click on amaker.

The only functional component of the class Avatar is a method named 
parser(), and it is in charge of reading the information off the attribute
file.

The following section now describes the implementation and design of our
prototype humanoid avatar, Avarcron.


2. Background   Top

Avarcron is implemented in a high-level language called Unicon, so as 
Unicron.  Unicon offers 3D graphic facilities and easy implementation in 
object-oriented methology.  And, the fact that it is platform-independent
makes it more attractive to use for development of a 3D CVE like Unicron.


3. Design   Top

Avarcron is composed of six body parts: head, body, two arms, and two legs.
Each body part is capsulated in a class (class head, class body, class arm,
and class leg), and the instances are aggregated into the class avarcron.



As the class avarcron inherits from the class Avatar, the body part classes 
inherit from a class called AvatarParts.  It holds a collection of commonly
used methods that the body parts may use often.

 Class: avatar
   Class: avarcron
      Class: avatarParts
	Class: head
	Class: body
	Class: arm
	Class: leg


4. Usage   Top

In order to use an avarcron, one has to open up a 3D window by calling
WOpen() in Unicon.  This means that avarcron can be used not only in Unicron
but in any 3D capable windows.

   john:= avarcron()
   john.initialze(n)  # where n is the name of .avt file without the extension 
   john.setup(x,y,z)  # x,y,z is the 3D coordinate where the avarcron initially 
		      # appears.


5. APIs for Driving   Top

The method that handles the movement of the avatar is actions(). The
method actions() takes one argument, a integer, which specifies which action
to take.  For instance, if a value 1 is passed as below, the avarcron would
move forward with its right leg and left arm moving forward while left leg
and right arm swing backward, creating a walking-forward effect.

   john.actions(1)

The following is a table of integer values along with their actions.

   value  |  actions
   ----------------------
     1    |  walk foward
     2    |  walk backward
     3    |  walk to right
     4    |  walk to left
     5    |  turn left
     6    |  turn right
     7    |  raise right arm
     8    |  raise left arm
     9    |  back to normal [1]
     10   |  initiating pointing [2]
     11   |  talking on
     12   |  talking off
     13   |  move pointer up
     14   |  move pointer down
     15   |  move pointer to right
     16   |  move pointer to left
     17   |  pointer arm, head back to normal

   [1] it brings every body part back in its origal state, that is,
       the standing-still position.
   [2] As seen here, pointing can be done with avarcrons.  This 
       command initiates the pointing by first setting the avarcron 
       standing-still then brining up the pointing hand up.