DESIGNING 3D WEB USING VRML

Bob HobbsIntroduction to Virtual Reality and Simulation

CE00166-1

Development Cycle

Target Platform

To establish your target computer platform you must ask yourself the following questions:

1.Who will be using my Synthetic Environment? 2.What hardware and software are they likely to be using? 3.How will my Synthetic Environment be delivered to

them? 4.When will my Synthetic Environment be finished?

Understand the Features & Limitations of the Technology

General Limits Polygon Count Textures Lights Sounds Filesize VRML Specific Limits No Shadow Casting No Reflections Performance

Plug-in Compatibility/Compliance

Storyboard and Project Documentation

Target Platform Preliminary Research Storyboard Sketches Interactivity User Interface Resource Requirements Project Timeline and Milestones

ImportingFrom ModelingSoftware

Find suitable model Modify Reduce Polygon Count

Edit Appearance

Material Properties Diffuse - colour of object Specular - highlight colour

on shiny objects Emissive - glow colour Ambient intensity Shininess - changes the

size of the highlight Transparency

Apply Textures File Formats

PNG - Portable Network Graphics

JPEG - Joint Photographic Experts Group

GIF - Graphics Interchange Format

MPEG1 - Motion Picture Experts Group

Assemble Scene

Modular Assembly Time_consuming Allows behaviours to be attached more easily Use DEF to allow cloning Use scene tree methodology

Using Inlines Uses existing model Scaling Cannot animate sub-assemblies

Environmental Objects

Background Texture Gradient Single Colour

Adding Lights No shadows More Faces - better

shading Limit to number of lights Different types of lighting

Lighting

Directional light Point Light Spot Light

Headlight - always on (deactivate after adding lighting)

Add Animation

Key Frame animation Interpolation Tweening Storyboard

Complex Interactions

Create Drag Sensors Create Switch Nodes Scripting

SensorsTouchSensor User clicks on, or rolls mouse pointer over object to trigger even

PlaneSensor User clicks and drags to move an object in the local X-Y plane

(left-right, up-down)

CylinderSensor User clicks and drags to rotate an object around its Y (up-down) axis

SphereSensor User clicks and drags to rotate an object freely around all axes

ProximitySensor Event is triggered when user enters a specified zone

VisibilitySensor Event is triggered when object enters or exits the user's view

TimeSensor When activated by one of the above sensors or a script the

TimeSensor outputs the absolute time plus fractional values

between 0.0 and 1.0 for a specified duration. It is used to "drive"

animation interpolators.

Collision* Not technically a sensor at all but a special grouping node. It

does, however, generate output events when the user collides

with the group so it is worth mentioning with the other sensors.

Scripting

Required when:- keeping track of an object's state (eg. is the door open or

closed?) when the interactions of one object are conditional on the

state of another (IF ... THEN ... ELSE type statements etc) any time mathematics is required (eg. PI or random

number generation or sine wave animation path etc) runtime creation of custom nodes (eg. build me a spiral

staircase 3 metres high etc)

Switch Nodes

Allows the same Node in the scene graph to switch between different groups

Possible uses: Changing fabrics for dress model Changing items on shelf Switching between open and closed door

Navigation and User Interface

Specify Method(s) of Navigation Create Viewpoints Hyperlinks and HUD (Head Up Display)

Specify Method(s) of Navigation

NavigationInfo Node Camera Avatar (see later Lecture) - also congigurable

Navigation Style Walk User affected by gravity Fly No gravity Examine Rotate scene around None No navigation controls - good for banner ads

or if you are creating your own controls Any User may choose any navigation they wish

Viewpoints

Allows several specialist views to easily navigate

Can be linked to sensors attached to objects

Hyperlinks and HUD Hyperlinks - any object can be linked to a

URL A HUD (Head Up Display) is a construct of

a number of VRML nodes and a ProximitySensor The ProximitySensor basically keeps track of where the

user is and feeds the group’s position and rotation into the group of objects that comprise the HUD to keep it positioned just in front of them at all times.

Packaging And Web Integration

Stores all files into one directory so that they can be easily published

An initial link to the .wrl file must be incorporated into the start-up page

Provided any separate files are in the same directory the seperatae .wrl files can be inlined or hyperlinked at will

Optimise and Test (General Guidelines)

Reduce the polygon count Reduce detail Build only what will be seen Modularity Scale Create Levels of Detail (LODs) Materials and Texturing

Publish

FTP to Host Keep same file structure