JReality

Java^TM Virtual Reality Applications
"CM Surveyor"^TM Usage Howto
Overview

Overview

The purpose of the CM Surveyor^TM browser is to address the twin problems of Browser Configuration and Browser Navigation described in the JReality^TM Technical Plan.

Browser Configuration

CM Surveyor is implemented as both a stand-alone Java3D^TM program, and as a Java3D applet. When run as an applet, it provides 3D web page capability in a traditional 2D web browser such as Netscape^TM. CM Surveyor is transparently downloaded when a compatible 3D web page is encountered with no special action on the part of the user. Operation in this manner requires that the user's web browser be Java3D capable.

While Java3D capable browsers are expected to be commonplace in the near future, currently no known web browser is Java3D capable as delivered. Fortunately, Netscape 6 can be easily configured to support CM Surveyor. Even so, the fact that any user configuration at all is needed implies that the goal of "no user configuration required" has not yet been met. However, when Java3D capable browsers become available, CM Surveyor is ready.

Browser Navigation

The current version of CM Surveyor takes important steps in solving the problem of Browser Navigation. Mouse-driven movement of an avatar (an arrow-like indicator of the view position) is fully functional in three sectional views. Precise positional control via entry of exact position coordinates is also operational. Other navigational improvements, such as keypad-driven movement, are planned for future releases.

Browser Coordinate System

Effective use of CM Surveyor is aided by an understanding of the coordinate system used. CM Surveyor uses the same coordinate system as Java3D, i.e., a right-handed rectangular coordinate system. Rotations follow the right hand rule, which states that the (+) rotation direction is the same as the curl of one's fingers if one were to grasp an axis with the thumb pointed along the (+) axis direction. Also, Java3D assumes the default view direction is in the negative Z (-Z) direction.

          +Y
           |
           |
           O------> +X
            \
             \
             +Z
                
   Right-Handed Rectangular
      Coordinate System

The standard convention for scene geometry developed for CM Surveyor is to position the "front" of the scene at the origin with the longitudinal axis of the Compartmentalized Model^TM extending in the +X direction. Thus, geometry for a ship or airplane would usually be defined as follows:

          +Y                       _____
           |______________________|_____|____
           |\                             __/
           | \___________________________/
           O------------------------------------> +X
            \ Front                      Back or
             \ or Bow                     Stern
             +Z
      
               Standard Orientation of
          Compartmentalized Model Geometry

This convention results in a default view of the left or port side of the Compartmentalized Model. The ship demo scene follows this geometry definition convention.

For Compartmentalized Models with no dominant axis, such as most buildings, an alternate convention is to define the geometry with the front of the model toward the +Z axis.

          +Y
   ________|_ Back of building
  |\       | \
  | \      |  \
   \ \_____|___\ 
    \ |    |    |
     \|____|____| Front of building
           O--------> +X
            \
             \
             +Z
              
     Alternate Orientation of
 Compartmentalized Model Geometry

This convention results in a default view of the front of the Compartmentalized Model. The store and house demo scenes follow this alternate geometry definition convention.

Browser Nomenclature

Some of the CM Surveyor menus use nautical terminology. There are several reasons for this:

Nautical terminology is definitionally more precise than common vernacular (a result of the unforgiving nature of seafaring, where misunderstandings are often fatal). CM Surveyor leverages this definitional precision.

Ships, including airships and starships as well as water craft, are particularly well-suited to geometrical definition using the Compartmentalized Model approach. Hence, the window layout and menu terminology of CM Surveyor have been developed to ensure compatibility with these application domains.

The author of CM Surveyor is trained as a naval architect.

For those who may not be familiar with nautical terminology, the following are the definitions of terms used within CM Surveyor:

bow -- the front of the vessel. For a CM Surveyor scene in standard orientation, the geometry nearest the X axis origin.

deck -- horizontal continuous surface on which people can walk. Called "floor" on land (but never on a ship, where "floor" has an entirely different meaning). For a CM Surveyor scene, refers to interior decks.

longit blkhd -- menu abbreviation for "longitudinal bulkhead", a partition (or "wall" in land terminology) that is roughly parallel to the centerline. For a CM Surveyor scene in standard orientation, an interior partition roughly parallel to the X axis.

outfit -- equipment added to the vessel after the primary structure of shell, decks, and bulkheads are in place. Includes furnishings and the like.

port -- the left side of the vessel, as determined when standing aboard the vessel facing the bow.

shell -- the exterior side and bottom of the vessel. More properly called "shell plating."

starboard -- the right side of the vessel, as determined when standing aboard the vessel facing the bow.

stern -- the back of the vessel. For a CM Surveyor scene in standard orientation, the geometry having the largest X coordinates.

transv blkhd -- menu abbreviation for "transverse bulkhead", a partition (or "wall" in land terminology) that is roughly perpendicular to the centerline. For a CM Surveyor scene in standard orientation, an interior partition roughly perpendicular to the X axis.

weather deck -- an exterior deck exposed to the weather. Roughly equivalent to "roof" on land, although people do not usually walk on roofs (except in action movies).

Starting CM Surveyor

If CM Surveyor is installed on your system, it may be run standalone by typing the command:

java com.jreality.surveyor.gui.Surveyor

Running a standalone copy in one window while browsing this Howto in another window is an excellent way to become familar with CM Surveyor. Standalone operation is also ideal when building compartmentalized models for 3D scenes and web pages. To obtain a copy of CM Surveyor for standalone use, go to the JReality download page.

When run as an applet over the web, CM Surveyor downloads and executes automatically when a compatible 3D web page is entered, providing your web browser is Java3D capable.

Howto Format

The remainder of this Howto is written in an experimental, stylized format intended to communicate more information in fewer words, and fewer bytes.

Overview - Browser Layout - Avatar Movement
File Menu - Personal Menu - Environ Menu - Section Menu
Fidelity Menu - View Menu - Hyperlinking