
Note: This is text version of Gengui.hlp.


                       G-Web User Guide
                            
                   G-Web World Builder


                            
                            
                    Version 4.0 Beta
                            
                            
                            
                Windows/NT Intel  Release

                            
                            
                            
                            
                            
                       User Guide
                            
                            
                            
                            
                            
                            
                            
                        Contents
                                                         
Contents                                           3

Introduction To G-Web
5
   What is G-Web - a quick overview
5
   The Importance of a Friendly Environment
5
   Versions                                        5

Getting Started
7
   Installation
7
   System Requirements
7
   System Files and Variables
7

Running G-Web
9
   The Interface Window
9
   The Graphics Window
9

G-Web Environments
10
   What is a G-Web Environment?
10
   Clearing an Environment
10
   Loading and Saving an Environment
10
   Exporting VRML
11

Resources
12
   What is a Resource?
12
   Resource Generation
12
   Resource Selection
12
   The Resource List
13
   Drag and Drop
14
   Resource Manipulation and Modification
15
   Selection Modes
15

G-Web Interface
17
   File Options
17
   New Project
17
   Open Project                                    17
   Save Project
17
   Export Project
17
   New Resource                                    17
   Open Resource
17
   Save Resource
17
   Editing Resources
18
   Cut
18
   Copy                                            18
   Paste                                           18
   Delete
18
   G-Web Tools                                     19
   Render Tool
19
   Translate Tool
19
   Orientate Tool
19
   Scale Tool
20
   Colour Tool
20
   Texture Tool
20
   Rename Tool                                     21
   G-Web Attributes
22
   Object Attributes
22
   Object Geometry Tool
22
   Object Hierarchy Tool
24
   URL Anchor
24
   Polygon Attributes
25
   Light Attributes
26
   Path Attributes
26
   Path Icons
26
   Path Selection
26
   Path Manipulation
26
   Path Creation
27
   Path Editing
27
   Path Interpolation
27
   Path Recording
28
   Path Playing
28
   Path Loading and Saving
29
   Path Visibility
29
   Path Assocation
29
   Viewpoint Attributes
29
   Sensor Attributes
29
   G-Web Options
30
   Toolbar
30
   Statusbar                                       30
   Markers
30
   Viewpoint Jump
30
   Verbose
30

The Toolbar                                        31
   File I/O
31
   Edit Operations
31
   Undo and Redo
32
   Selection Options
32
   Scale Sensor                                    32

                            
                  Introduction To G-WEB

What is G-Web - a quick overview

G-Web  has  been  designed as a VRML Authoring  tool.  It
provides  a means of interactively manipulating resources
such  as  graphical  objects,  textures,  viewpoints  and
lights,  in a simple, efficient and intuitive way.  G-Web
can  be  used to combine these resources together into  a
single  coherent environment for later editing or  export
as a VRML file.

G-Web  is  based on the VR authoring library WorldToolKit
and  some  of  the  functionality  of  G-Web  is  related
directly  to these libraries. For this reason  there  are
some  areas of G-Web functionality that are not supported
by the VRML version 1.0 standard. G-Web uses its own file
format  (.gen)  which  will preserve  all  aspects  of  a
project  created  with  G-Web.  Any  environment  can  be
exported  by  G-Web as VRML format, although  unsupported
aspects of the environment will be ignored.

The Importance of a Friendly Environment

G-Web  improves environment development with its  ability
to  save  and load environments which have been  created.
These   environment   (.gen)  files   contain   all   the
information needed to rebuild the environment.

G-Web   allows  you  to  record  references  to  specific
graphical  objects,  lights etc. on  disk  so  that   the
environment   file  need  only  contain  the  information
necessary,  for  example, to position and  orientate   an
object.  The  actual 3D object resides on  disk  in  your
project directory.

This  method  of  using references to  existing  objects,
textures,  etc. means that the  environment file  can  be
written  out in an ASCII format enabling it  to  be  read
using a text editor.
                            
Versions

There are three versions of G-Web available.

G-Web WinLite

This  version is based on Intels' 3DR graphics  libraries
and  has  a  number of limitations. It will run  on  both
Windows 3.1 and Windows NT.

G-Web NT

This  is  the  full version based on the OpenGL  library.
This version will only run under Windows NT - Intel.

G-Web SGI

This   is   the   full   version  for  Silicon   Graphics
workstations.

                            
                     Getting Started

The following topics discuss the basic issues relating to
G-Web:

Installation

See distribution media.

System Requirements

G-Web  installs on hard disk requiring less than  5MB  on
most platforms.

System Files and Variables

To execute G-Web simply ensure that G-Web is on your path
or  in  the  current  directory and  run  as  a  standard
application on that platform (or see the readme.txt  file
on the distribution media.)

G-Web  can  be  run with numerous options. These  can  be
placed  in  any  order  prefixed  by  a  minus  sign  and
seperated  by a space. Each argument contains information
on  how  to  run the editor. These arguments follow   the
gengui command. G-Web's executable is called gengui.

These arguments can be summerised as follows:

-<sensor>[comport][unit number][v | m]

Therefore the line:

 gengui -mvm -s1vm

Passes  two  arguments which contain information  on  the
sensor types.

The  -mvm  indicates that the mouse is  to  be  used  for
manipulating objects and viewpoints.

The  -s1vm  indicates that there is a Spaceball connected
to  serial  port  1  and  that  it  is  to  be  used  for
manipulating objects and viewpoints.

The  mouse is a special case sensor (because both systems
always  have a mouse attached); it can also  be  used  to
select resources and polygons. In most cases G-Web  works
well  using  a  Spaceball  or  Spacemouse  to  manipulate
objects and  viewpoints and a mouse to select resources.

(A  full list of possible command line arguments is given
in the readme.txt file)

G-Web WinLite

The  command line arguments are set using the  WTKWIN.INI
file. The section at the end of the file headed by [args]
allows  the user to specify which sensors to look for  on
start  up.  G-Web looks in the G-Web directory  for  this
file.

G-Web WinNT

The  command  line  arguments are  set  via  the  Program
Managers icon. This can be accessed by selecting the icon
and  pressing  Alt+Enter. A dialogue will  open  and  the
command line arguments can be altered.

G-Web SGI

Command line arguments can be set from the run file.

Information on other versions is available on request.
                            
                      Running G-Web

G-Web presents the user with two windows:


The Interface Window

This  is  the  main  window where all  the  commands  are
issued:

This window consists of:

1.   A  resource  list  containing  details  on  all  the
resources in the environment.
2. A Toolbar with a series of buttons which perform short
cuts to menus.
3. A status bar giving G-Web information.
4.  A  menu bar providing more detailed access to options
and tools.


The Graphics Window

This  main  window shows a graphical view of the  virtual
world  being edited. Graphical resources can be  selected
in   this  window  using  the  mouse  pointer  (selecting
resources).


In  versions  other than G-Web WinLite it is possible  to
have more than one graphics window open.fa

                            
                   G-Web Environments


What is a G-Web Environment?

An  environment is made up of G-Web resources. Details of
these   resources  can  be  recorded  and  saved  as   an
environment  file  (.gen format)  from  which  G-Web  can
reconstruct the environment at a later date.

An  environment can also be exported as VRML at any stage
in  the development process. Note that G-Web cannot  read
in  VRML as yet and that a project should be saved in the
.gen  format  if the user wants to reload and  alter  the
environment within G-Web.


Clearing an Environment

G-Web   will   starts  up  with  a  default  environment,
containing any sensors created with the command line,  an
environment,  a  window and a viewpoint.  The  background
colour defaults to black, the ambient light intensity  is
reset and the viewpoint defaults to the origin.

Environment  resources currently in  the  editor  can  be
cleared  by  making a new environment. The user  will  be
asked  if  they wish to save any of these to disk  before
clearing the environment.


Loading and Saving an Environment

G-Web  defaults the environment file extension  to  .gen,
and  the  user  may  wish to follow this  convention.  An
environment variable known as WTMODELS is used  to  point
to  the  project  directory  for  the  environment.  When
saving,  G-Web will place its environment files  in  this
project  directory. Note that in order to export  a  VRML
version of an environment all the models and textures for
that  environment  must be available  to  G-Web  via  the
project directory.

  Loading  an  environment will  overwrite  any  existing
environment in G-Web.

G-Web WinLite

The WTMODELS variable is set using the WTKWIN.INI file. G-
Web looks in the directory it is run from for this file.

G-Web WinNT

The  WTMODELS variable is set as an environment  variable
from  the  System  Settings  dialogue  accessed  via  the
Control Panel.

G-Web SGI

The  WTMODELS variable is set as an environment  variable
from the run file.


Exporting VRML

A  project  can  be exported from G-Web in  a  VRML  file
format  which  can  be  read by a VRML  browser  such  as
WebSpace.  Textures  can  be written  out  in  either  an
external file format or inline as an SFimage node.

Beta  Note: Inlines, point sets, level of detail,  fonts,
info  nodes  and orthographic cameras are unsupported  in
this  release. If texures are written out as an  external
file  it  is up to the user to convert the file from  the
native  format  to  the  format  chosen  in  the  extents
dialogue box.


                        Resources

Resources can be created and manipulated using G-Web

What is a Resource?

An  environment  in G-Web is made up  from  a  number  of
building blocks, these are known as resources. G-Web  can
import   various  graphical  object  file  formats   from
external  sources including .dxf, .nff and .3ds.  Texture
files  are  also  regarded  as  resources.  Textures  are
applied  to objects in .tga format under windows or  .rgb
format  on Silicon Graphics platforms. If the user wishes
to  apply  a texture that is in a different format  (i.e.
.gif,  .bmp) then G-Web will attempt to convert the  file
format of the texture to the appropriate texture for  the
platform.  Lights  and viewpoints are  also  regarded  as
resources,  as  well  as graphics  windows  and  sensors,
although these are not exported in the VRML file.


Resource Generation

Creatable resources available to the user fall into  five
categories :

1. Objects
2. Lights
3. Paths
4. Viewpoints
5. Windows

These   resources  can  be  created  from  the  File->New
Resource  menus.  Selecting one of these  resources  will
invoke  a  dialogue  box  in  which  information   on   a
particular  resource  can  be  edited.  To  generate  the
resource click the 'create' push button. Note that  paths
and windows are not exported in the VRML file format.


Resource Selection

There are two main methods selecting a resource in G-Web:

1.From resource list in the interface window.

2.From the graphics window.

See Selection Modes

The Resource List

The  resource list contains information on all  resources
in the environment.

Types  of  resource  are represented by  different  icons
which  appear  next to the resource name in the  resource
list.

These are listed below:

      The Environment

      Graphical Object

      Viewpoint

      Window

      Light

      Sensor

      Path

      Pathnode

      Polygon

      Texture

      UV Mapping Tool

      Object Axes



At the root of every project is an environment icon. This
can  be selected and allows the user to change attributes
that  affect the entire universe, for example the ambient
light  or  rendering mode. All other resources appear  as
children  of the environment and are listed by  type  and
then  in  alphabetical order. Further details  of  object
types can be obtained by right clicking on the object  in
the  resource list. The relationship between windows  and
viewpoints is shown by a hierarchical link.

A  window may have more than one viewpoint linked to  it,
but  can  never be without one. Viewpoints, like objects,
can  be   dragged and dropped within the resource manager
window in order to alter hierarchy links.


Drag and drop resources

Building Hiearchies

Objects  can  be dragged within the resource list  window
onto  other objects to build hierarchies.  Any  graphical
object  can be picked up by left clicking on its line  in
the  interface window whilst  holding down the shift key.
The mouse event will only be interpreted as a drag if the
shift key is  already held down.

If  the  left mouse button is held down and  moved  to  a
different  line in the  interface window then the  cursor
icon  will  change shape to indicate that the  object  is
being dragged.

If   the object is dragged out of the interface window or
to  a  line where there is no valid G-Web resource   then
the cursor will change to a noentry sign.

  If  the  object is dragged over a valid G-Web  resource
other than  a graphical object then the user will see the
object and a noentry sign as the cursor.  The cursor will
change  to a pair of linked objects to indicate that  the
drag  object can be dropped to form a hierarchy. To  drop
the object release the left mouse button.

When an object is dragged it is detached from any parents
it  might have, but the hierarchical  structures  of  any
objects  linked as children are maintained.  This  allows
the  user  to detach whole  hierarchical structures  from
one object and reattach them to other objects.

A  hierarchical  structure can  be  broken  by  the  user
dragging an object to the environment line  at the top of
the interface window. A pair of scissors will appear next
to the object cursor when over  this line indicating that
the  link can be severed.  Note that this cuts any  links
between  the  object being  dragged and its  parents  but
does  not affect any child links. Thus dropping an object
from  the base of a  hierarchy onto the environment would
have no effect as the object has no parents.

It  is  not  possible for objects to form a  hierarchical
loop and the user will be prevented from  performing such
links by G-Web.

Changing the viewpoints window.

The window to which a viewpoint renders can be changed by
dragging a window to another  viewpoint. As with  objects
the  user will see the cursor change to a no entry   sign
if  the cursor is dragged out of the interface window  or
to a line where there is no valid G-Web  resource. If the
window is over a valid resource the cursor will be window
shaped  with  a no entry sign, a  viewpoint linked  to  a
window  sign appearing when over a viewpoint,  indicating
that the window can  be dropped.

Non draggable types.

It  is  not posssible to drag the other types of resource
in  the  interface  window, for  example   viewpoints  or
sensors.  If one of  these non-draggable types is  picked
up  by the user then a no entry  sign will appear at  the
cursor with the types icon beside it, indicating what the
user is attempting to  drag.

Resource Manipulation and Modification

Tools  provided for the modification and manipulation  of
resources  are  obtained from the  tools  and  attributes
menus on the menu bar.

Selection Modes

Single selection mode

A  resource can be selected using the mouse, provided  G-
Web is in Pick Resource mode. This mode can be toggled on
by  clicking  on the large push button in  the  interface
window, the state changing between Fly Resource and  Pick
Resource.

Pointing  at a resource in a graphics window  (whilst  in
Pick  Resource  mode) and clicking with the   left  mouse
button  will toggle its selection. The selected  resource
will be highlighted using a red  bounding box, indicating
that it is the primary selected resource.

To  select  a  resource from the interface window  simply
select  it  from  the  list box.  To  indicate  that  the
resource  is  the selected primary its text  colour  will
change to red.

Selection  of resources via the interface window  is  not
dependent   on  being  in  Pick  Resource  mode,   unlike
selection via a graphics window.

Multiple selection mode

In  this  mode  more than one resource can  be  selected.
Multiple selection mode is turned on via a toggle  button
on   the toolbar. If there are no current selections then
the first resource to be selected is highlighted  with  a
red  bounding  box. This is the primary  resource.  If  a
further  resource  is  selected  then  this  becomes  the
primary   resource  and  the original  is  demoted  to  a
secondary  resource.  This is highlighted  with  a  white
bounding  box.   There  can  only  ever  be  one  primary
resource,   but  there  can  be  a  number  of  secondary
entities. Non selected items appear grey in the interface
window;  whilst  the primary resource is  highlighted  as
red, secondaries resources are black.

Deselecting Resources

All  selections can be canceled with the deselect  button
on  the toolbar. A single resource can  be deselected  by
toggling  the  selection off by clicking on  it  via  the
interface or graphics windows.

                            
                     G-Web Interface

File Options

This menu provides access to the file i/o and new
resource creation.

New Project

Clears the universe. All reources are deleted and the
environment is reiniatialised to the startup state.

Open Project

Allows a G-Web environment file (.gen) to be loaded. It
is not possible to merge more than  one environment file
into G-Web.

Save Project

The environment is saved to disk as a G-Web environment
file (.gen). This is in ASCII format  and contains a full
description of the environment. It is possible to edit
this file using a text  editor if required.

Export Project

  A  project  can be exported from G-Web in a  VRML  file
format  which  can  be  read by a VRML  browser  such  as
WebSpace.

New Resource

Allows the user to generate new resources

Open Resource

  Allows the user to load resources from disk. These  are
either object geometries or paths.

Note:  Paths  are  not supported in the VRML  format  and
cannot be exported.

Save Resource

Saves the selected resources.


Editing Resources

G-Web can edit resources via its own clipboard.

Cut

Any  selected  resources can be cut from the environment.
The resources are removed from the environment and copied
to the clipboard. They remain available to be pasted back
into  the universe until the next  cut or copy operation.
A  new  cut operation will overwrite any objects  in  the
clipboard

Beta  Note: Paths, Viewpoints, Windows and Sensors cannot
be cut from the environment at present.

Copy

Any selected resource can be copied to the clipboard. The
selected resource is not removed from the environment.  A
copy  of the resource is then available for pasting  into
the  environment at a later stage until the next  cut  or
copy  operation. A new copy operation will overwrite  any
previous copy operations.

BetaNote:  Paths, Viewpoints, Windows and Sensors  cannot
be copied from the environment at present.

Paste

Any  resource in the clipboard buffer will be pasted into
the environment at a position  in front of the viewpoint.
A  unique name is required for each new resource. If  the
verbose  mode  is  enabled the  user  is  able  to  paste
selected items from the clipboard.


Delete

Any   selected   resources  can  be  deleted   from   the
environment.

Note:  if  a  resource is deleted it cannot be undeleted.
However,  Objects  and Paths can be reloaded  from  disk.
Frequent   saving  of  environments  and   resources   is
therefore recommended.


See Toolbar Edit Options .

                            
                       G-Web Tools

The individual options in this menu act on resources
within the universe.


Render Tool

Selecting this option brings up a window with a series of
buttons to control the way in which  the resources in the
universe are rendered.

For  versions  other than G-Web WinLite the  render  tool
will  operate  on whatever is selected.  If  a  graphical
object  is  selected then the render tool will allow  the
user  to  set the render state of that object  to  either
wireframe  or  solid. If any other kind  of  resource  is
selected  as  primary or if there are no selections  then
the  render tool will affect the  state of the  universe,
although  graphical objects will maintain any  previously
set  render  states. For the WinLite version  the  render
tool  affects the way the entire environment is  rendered
and the user is unable to export individual object render
states.  The other versions of G-Web will allow the  user
to  export an object as either wireframe, flat shaded  or
gouraud shaded.



Translate Tool

This  tool  translates the selected resources within  the
universe. Moving the slider bars translates the  resource
along  the  appropriate  axis  in the  chosen  coordinate
system. The precise position of the resource can  be  set
by  entering  values in the edit boxes and  clicking  the
'set  absolute' push button. Note that if  a  polygon  is
selected  the  tool  will  operate  on  the  texture  (if
applied) rather than the polygon itself. Only the X and Y
slider bars have any effect on the texture's position.


Orientate Tool

This  tool  rotates selected resources around  their  own
pivot  point   in the selected frame. Moving  the  slider
bars will rotate the ressource. Absolute  orientation can
be set by entering values in the edit fields and clicking
the 'set absolute' push button. Note that if a polygon is
selected  the  tool  will operate  on  the   texture  (if
applied)  rather  than the polygon  itself.  Only  the  X
slider bar has any affect  on the texture's orientation.


Scale Tool

This  tool  scales selected resources about  their  pivot
points.

The  resources selected can be scaled in one of two ways.
The  Absolute scale of a resource can be set by  entering
the  size  of  the  object in the X,Y  &  Z  edit  fields
provided  and  then clicking on the 'set absolute'   push
button.  The  other method of scaling is  by  moving  the
slider  bars. This has the advantage of being interactive
and  the  resource can be seen changing size. By  default
the  maximum increase or decrease in scale of an resource
is  set to two times, but this can be changed by clicking
on  the up and down arrow icons beside the maximum offset
edit  field. Note that if a polygon  is selected the tool
will operate on the texture (if applied) rather than  the
polygon  itself. Only the X slider bar has any affect  on
the texture's scale.


Colour Tool

This tool will colour selected resources.

The  operation  can be performed by either selecting  the
colour  in  the bitmap or setting the colour values  from
the slider bars.


Texture Tool

This tool applies bitmap textures to resources.

There  are  two  modes of texturing available  in  G-Web,
either  facetted  or  draped.  Draped  textures  are  not
available on the G-Web WinLite version.

The  appropriate texture can be found from  the  disk  by
using the browse facility which brings  up a thumbnail of
the  texture  in  the window. This texture  can  then  be
applied to the resource using faceted texture mapping, by
clicking  the  'apply'  push button.  If  draped  texture
mapping is available then either a spherical, cylindrical
or  planar texture mapping tool can be generated via  the
texture  tool  dialogue  box. The  texture  mapping  tool
appears as a wireframe object associated with the  object
to be textured.

In order to apply a texture to an object the texture must
be  selected as the primary resource. This can be done by
right clicking the object with which the texture tool  is
associated in the interface window's resource list.  This
reveals a list of attributes as children of the object in
the  resource list. The texture tool should appear as one
of  these  attributes  and can be selected  with  a  left
click.  Once selected the tool becomes active and  allows
the  user to apply the texture to its parent object. Note
that  the  tool  can  also be repositioned  interactively
whilst  selected. This allows the texture to  be  'flown'
over   the   surface   of  the  object   and   positioned
interactively.

The  types  of  image format which can be used  are  RGB,
Targa, Windows BMP and GIF formats. G-Web requires a .rgb
file format on Silicon Graphics machines and targa format
on  other platforms to apply textures to resources, so if
a  different format is selected a conversion takes place.
This process will suggest a filename for the new image.

Rename Tool

This tool is used to rename a resource. Type the new name
into the edit field provided. Names must be less than  32
characters and have no white spaces.


                    G-Web Attributes

This menu allows the attributes of resource to be edited.


Object Attributes

The  sub  menu  from this option provides tools  for  the
modification  of  the   geometry of   an  object  or  the
creation of a hierarchy of objects.


Object Geometry Tool


An  object can have its attributes altered either at  the
object  level  or at  polygon level. The Trimesh,  Inside
out, Normals and Single/Double sided tools will work  for
either objects or polygons.

Reducing level of detail

Rebuilds  the  object with less detail. Sometimes  useful
for    getting   simplified  versions  of  the   object's
geometry.


Tri-mesh

This  will produce a replica of the object but  with  all
polygons  reduced  to tri-mesh. This is  useful  if   the
object  is to be distorted as tri-meshed object can  only
have coplanar polygons.

Optimise

This option scans the selected object optimizing polygons
which   can   merged  together  without    altering   the
appearance  of  the object. Only adjacent polygons  which
are  coplanar and share the same  colour or texture  will
be merged.

Optimization  is  very  useful  for  tidying  up   models
imported from third-party CAD modelers which  often  only
export  tri-meshed geometries, generally making 3D models
more  polygon efficient. This  option is the opposite  of
tri-mesh (above).

Add/ remove normals

Adding normals to object vertices allows gouraud shading.
G-Web can also remove normals from an object, which  will
make  it  appear flat shaded even if the gouraud  shading
flag is set.


Setting single sided / both sided

These  commands  affect whether the  object  is  rendered
single sided or both sided.

Toggle visibility

Makes  an  object either visible or invisible. Note  that
although  an   object is made invisible it  is  not  only
still  part  of  the  simulation but still  part  of  the
environment  and  thus   incurs a  significant  rendering
overhead.

Toggle add/remove

Removes or adds an object in the environment. The  object
remains   part  of  the simulation but has  no  rendering
overhead. The object can still be selected via  its  user
name.  This option is very useful when working with large
models which run with a very slow frame rate.

Setting pivot points and local axes.

A  graphical object's pivot point icon can be  turned  on
and  off. When on, a set of colour-coded  (red - X, green
-  Y,  blue  -Z) axes becomes visible, the positive  axis
direction being indicated by the white tips on each axis.

The  axes  are centered on the object's pivot point   and
are  orientated with object's local axes. These can  then
be changed by selecting the object's axes.

When  the  object's  pivot points are  highlighted  as  a
primary  object  they can be manipulated like  any  other
resource, either via a sensor or with the resource tools.
Changes  in  the local axes' orientation and pivot  point
position are not transferred to the object until the axes
are no longer the primary resource.

Decimating an object.

The  user specifies the number of polygons that the  they
wish  to have removed from the object. The tool will then
attempt  to  remove  these without changing  the  overall
shape of the object.

Beta  Note:The  tool does not support the  decimation  of
objects that are texture mapped .


The Object Hierarchy Tool

Object hierarchies

A  secondary  object can be attached to a primary  object
using the hierarchy tool. The primary object becomes  the
parent  and the secondary becomes the child. If  multiple
secondary  selections have been made then all objects  in
this  secondary  selected  set  become  children  of  the
primary  object.  Links  can also  be  deleted  from  the
primary   selected   object  via  the   hierarchy   tool.
Hierarchies  are  graphically  represented   within   the
interface window's resource list.

Beta  Note: All hierarchical attachments are written  out
to  the environment file (.gen) but are not yet reflected
in the VRML file.

Warning - Multiple hierarchical links are permitted by G-
Web. Any translations or rotations of  the parent objects
will  be  multiplied by the number of attachments between
objects.  Be careful not to  accidentally attach  objects
to  each  other more than once as the interface  resource
list  has  no  way  of  representing  multiple  linkages.
Objects  should  not be linked back on themselves.  G-Web
will  trap  any attempts to attach an object  to  itself,
even via other objects.


URL Anchor

A  URL Anchor can be applied to an object in G-Web. It is
entered  as a text string and associated with the primary
selected  object. The URL Anchor is written out when  the
project is exported as a VRML file.


Polygon Attributes

Selecting a polygon

A polygon can be selected with the mouse, using the right
button  when  in mouse pick mode. A polygon may  then  be
edited  like any other object. Multiple polygons  can  be
selected by using the polygon selection tool found on the
menu  under Attributes/Polygon. Polygon selection can  be
propogated  according  to how many  verticies  a  polygon
shares  with the currently selected polygon, and  whether
the  angle  between their normals  is above  or  below  a
certain  value.  The propogate selection tool  will  only
work if you have the pick many mode turned on.


Note: A polygon may be coloured, textured or deleted.  At
present it cannot be moved, cut, copied, pasted or named.


Deleting polygons

The selected polygon is removed from its object. The user
will  be  warned  if  this is the only   polygon  in  the
object;  if the last polygon of a object is deleted  then
the  object itself will be deleted  from the environment.
Once  a polygon has been deleted from an object it cannot
be  replaced  by  G-Web,  so be careful when  overwriting
original models.


Light Attributes

The  attributes  which can be modified for  a  light  are
dependent on the type of light which has been selected.

Directional Lights

The  only  modification which can  affect  a  directional
light  is intensity. Modification is made by sliding  the
scroll  bar  or entering a value in the edit field.  This
can be set to any value  between 0.0  & 1.0.

Point Lights

For  a  point light the intensity and exponent attributes
can  be  changed, again this either by sliding the scroll
bar  or  entering a value into the edit field  below  the
slider bar.

Spot Lights

All of the attributes in the window can be set for a spot
light.

  G-Web WinLite : Point and Spot Lights are not supported
for this version.

Path Attributes

This tool can be used to create and manipulate paths.
Paths are not supported by VRML version 1.0.


Path Icons

Paths are represented in G-Web as a combination of a path
icon and pathnode icons. The path icon is similar to  the
light  icon in that it acts as a handle on the  path  for
the  user, and can be used to select  and manipulate  the
path. Pathnode icons are the representation of the  nodes
which  belong to the path icon. The two always share  the
same colour and the path icon is snapped  to the position
of the first path node whenever possible.


Path Selection

A path can be selected in the same way as a light via its
icon.  Path nodes can be selected via the path node icon.
Moving  the path icon will cause the whole path  to  move
and  objects  playing down the path will also  follow.  A
path  node  or  group of path nodes can be  selected  and
modified individually.

Performing  a  delete operation on a selected  path  icon
will remove the whole path from the environment, but  any
associated  objects will be left intact. If only  a  path
node  is  selected  then  the  individual  path  node  is
removed.

BetaNote:  Path nodes can be scaled in this  release  but
this  scaling  is  not reflected in the environment  file
and so can not be preserved.


Path Manipulation

Pathnode  icons  are hierarchically linked  to  the  path
icon.  The  icon can then be positioned using a   sensor,
with  the pathnodes moving relative to the icon.  A  path
can   be   repositioned  even  when  the  pathnodes   are
invisible  or  the  path  is  playing.  A  path  can   be
repositioned  using the resource position  and  orientate
tools. Pathnode icons themselves can also be selected and
repositioned in the same way.


Path Creation

A  path can be created from the path tool. A user name is
requested and  defaults supplied. The path is marked by a
path  icon, in the shape of an arrow.  The icon is  given
the orientation and position of the view point when first
created.   A  newly created path is white. Paths  can  be
coloured using the colour tool and this is a useful   way
of  distinguishing paths. Path colours are written out to
the environment file.


Path Editing

Deleting a path

A  path  can be deleted providing that the path  icon  is
selected. All the path node icons will be deleted  from G-
Web although the path's .pth file will remain unaffected.

Deleting a node
A single path node can be deleted if selected.

BetaNote:  Its not possible to cut, copy or paste  either
paths or path nodes at present.


Path Interpolation

The  interpolation editor can be accessed from  the  main
path tool.

There are three interpolation methods supported by G-Web.
The  path  to  be  interpolated must be selected  as  the
primary resource. The interpolated path is created  as  a
new  path,  and is coloured red. A new filename and  user
name  for the interpolated path are required and defaults
are supplied.


Path Recording

The  record  editor can be accessed from  the  main  path
tool.

Nodes  can  be  added  to the primary  selected  path  by
recording  the  movement  of the  viewpoint.  The  record
editor  allows the user to begin recording and  terminate
recording   of   the  viewpoint  whilst   it   is   being
manipulated. The sample rate for recording  can  also  be
set.

A  single  path node can be added to the primary selected
path  at  any  time.  The new node  will  be  given   the
position and orientation of the viewpoint when added.  If
the  path  nodes are set to invisible then the  new  path
node will not be visible.


Path Playing

The  path play editor can be accessed from the main  path
tool.  All the functionality of the play  editor  applies
to the primary selected path.

The  viewpointand graphical objects can be played down  a
path, stepped down or up it a node at a time or moved  to
its  first  or  last  node. The  play  direction  can  be
reversed  whilst  the  path is playing.   The  path  will
continue  to play until it is stopped or extra nodes  are
recorded on to it.

Path  play  parameters CONTINUOUS, OSCILLATE and  DEFAULT
can  be  set,  although the path  must  be  stopped   and
retarted for any mode changes to take effect.

All  the play details associated with a path  are written
out to the environment file.

If  an  environment with a path that is playing is loaded
then it must be selected before the path  can be stopped.

Play tools apply to both a viewpoint being played down  a
path or to an associated object.


Path Loading and Saving

A selected path can be saved to disk from within G-Web at
any  time.  Paths are written into the project directory.
It is possible to enter a user name for  the path when it
is  loaded. A path icon is created for the path  once  it
has  been  loaded and is then snapped to the  first  path
node  of the path loaded, unless the loaded path  has  no
nodes.


Path Visibility

This toggles the pathnode icon's visibility. This can  be
useful  if  a path contains a large  number of nodes.  It
does not affect the path icon.


Path Association

To  associate  an object with a path, the  path  must  be
selected  as the primary resource and  there must  be  an
object selected as a secondary resource. If there is more
than  one  secondary  selected  resource  then  the  most
recently selected object is associated with the path. The
object will then play down the path. Only one object  can
be associated with any one path.



Viewpoint Attributes

This tool is used for the modification of the attributes
of a viewpoint.


Sensor Attributes

This  tool provides the facility to modify the attributes
of  the  sensor.  The  constraints checkboxes  cause  the
sensor  to  toggle movement or rotation  on/off  in  that
direction. The sensitivity scroll bars modify the  amount
of  movement or rotation applied in the G-Web  world  per
unit movement of the sensor.

                      G-Web Options

This menu allows various G-Web options to be turned on or
off.


Toolbar

This allows the user to turn the toolbar on or off.


Statusbar

This allows the user to turn the statusbar on or off.


Markers

This allows the user to turn the selection markers
(e.g.selection bounding boxes, polygon markers) on or
off.


Viewpoint Jump

When  ticked this enables the user to select a  viewpoint
from  the  graphics  window and have the  window  it  was
selected  from  render  the environment  from  the  newly
selected viewpoint.

G-Web  WinLite  -  With this implementation  selecting  a
viewpoint via the resource list will cause the window  to
jump. This does not occur for the other versions as there
maybe more than one window.


Verbose

G-Web will print more detailed information to the user
via the I/O window when verbose mode is turned on.

                       The Toolbar

The tool bar icons are arranged in groups:

File I/O


 Open Project

Load a G-Web .gen file and all the resources associated
with it.

 Save Project

Saves a G-Web .gen file.

Edit Operations


 Cut Resource

Remove a resource from the universe and put it in the
clipboard.

 Copy Resource

Copy a resource to the clipboard.

 Paste Resource

Paste a resource from the clipboard to the universe.

 Delete Resource

Delete a resource from the universe.

Undo and Redo

 Undo Last Position

 This will restore the position of a selected resource
that has been moved

 Redo Last Position

 This will restore a resource to its position before the
undo button was used


Selection Options

 Deselect All

 This will remove all selections from resources


  Toggle Selection Mode

 This toggles the selection mode between pick single and
pick many. When in pick many mode more than one resource
can be selected, the last resource to be picked being the
primary

Viewing Tools

 Find Primary

Move the viewpoint to the primary selected resource.


 Fetch Primary

Move the primary selected resource into view.

Note  that when there are  multiple viewpoints  the  last
selected viewpoint is recorded and is indicated  with  an
arrow  in  the interface window. If the user  'finds'  or
'fetches' an object then it will be to the last  selected
viewpoint.

 View All Entities

Move the viewpoint to a position where all the resources
in the universe can be viewed.

 Toggle Follow Mode

When moving the selected resource the viewpoint follows
it.

Scale Sensor



Scale   sensor  relative  to  the  size  of  the  primary
resource.  If  there is no resource selected  the  sensor
will scale relative to the size of the whole universe.

