Vrml 2.0 Scene Graph Structure: Nodes

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VRML 2.0 Scene Graph Structure Nodes Group

Transformation

Shape

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Shape Node: Contained Nodes

Shape appea rance

col or

c

norm

d coor r olo

rd coo

al

Indexed Face Set

Indexed Line Set lor

coo rd

Point Set

Coordinate

Color

Normal

ran

sfo

rm

Texture Transform

Elevation Grid r colo

te xC al

rm no

FontStyle

reT

Image, Movie PixelTexture

Material

co

fon tSty le

Text

m

tex tu

oo rd

texCo ord

Box Cone Cylinder Sphere Extrusion

l ria e t a

texture

ge om et ry

Appearance

Texture Coordinate

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Text Node Definition fontStyle Node Definition Text {

}

exposedField exposedField exposedField exposedField

FontStyle { field field field field field field field field field }

MFString SFNode MFFloat SFFloat

MFString SFBool MFString SFSring SFFloat SFFloat SFString SFBool SFBool

string fontStyle length maxExtent

[] NULL [] 0.0

family “SERIF” horizontal TRUE justify “BEGIN” language ““ size 1.0 spacing 1.0 style “PLAIN” topToBottom TRUE leftToRight TRUE UML

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Appearance & Material Nodes

Appearance { exposedField SFNode exposedField SFNode exposedField SFNode } Material { exposedField exposedField exposedField exposedField exposedField exposedField }

SFFloat SFColor SFColor SFFloat SFColor SFFloat

material NULL texture NULL textureTransform NULL

ambientIntensity 0.2 diffuseColor 0.8 0.8 0.8 emissiveColor 0 0 0 shininess 0.2 specularColor 0 0 0 transparency 0

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Texture Node Definitions ImageTexture { exposedField field feild }

MFString SFBool SFBool

url repeatS repeatT

[] TRUE TRUE

PixelTexture { exposedField field feild }

SFImage SFBool SFBool

image repeatS repeatT

0 0 0 TRUE TRUE

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Texture Node Definitions, Continued

MovieTexture { exposedField exposedField exposedField exposedField exposedField field field eventOut eventOut }

SFBool SFFloat SFTime SFTime MFString SFBool SFBool SFFloat SFBool

loop FALSE speed 1 startTime 0 stopTime 0 url [] repeatS TRUE repeatT TRUE duration_changed isActive

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Lighting in VRML 2.0 Directional Light Source DirectionalLight { exposedField exposedField exposedField exposedField exposedField }

SFFloat SFColor SFVec3f SFFloat SFBool

ambientIntensity color direction intensity on

0 1 1 1 0 0 -1 1 TRUE

Directional lights are “scoped” to illuminate only objects in their group.

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Lighting in VRML 2.0 Point Light Sources PointLight { exposedField exposedField exposedField exposedField exposedField exposedField exposedField }

SFFloat SFVec3f SFColor SFFloat SFVec3f SFBool SFFloat

ambientIntensity attenuation color intensity location on radius

0 1 0 0 1 1 1 1 0 0 0 TRUE 100

Scoping for the PointLight is given by the radius field, beyond which no objects are illuminated

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Lighting in VRML 2.0 Spotlights

SpotLight { exposedField exposedField exposedField exposedField exposedField exposedField exposedField exposedField exposedField exposedField }

SFFloat SFVec3f SFFloat SFColor SFFloat SFVec3f SFFloat SFVec3f SFBool SFFloat

ambientIntensity 0 attenuation 1 0 0 beamwidth 1.570796 color 1 1 1 cutOffAngle 0.785398 direction 0 0 -1 intensity 1 location 0 0 0 on TRUE radius 100

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Transform Node Definition Transform { enventIn eventIn exposedField exposedField exposedField exposedField exposedField exposedField field field }

MFNode MFNode SFVec3f MFNode SFRotation SFVec3f SFRotation SFVec3f SFVec3f SFVec3f

addChildren removeChildren center children rotation scale scaleOrientation translation bboxCenter bboxSize

0 0 0 [] 0 0 1 0 1 1 1 0 0 1 0 0 0 0 0 0 0 -1 -1 -1

Order of application: T(translation) • T(rotation) • T(scale) {children}

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GroupNode Definition Transform { enventIn eventIn exposedField field field }

MFNode MFNode MFNode SFVec3f SFVec3f

addChildren removeChildren children bboxCenter bboxSize

[] 0 0 0 -1 -1 -1

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Viewing in VRML 2.0 Viewpoint { eventIn exposedField exposedField exposedField exposedField field eventOut eventOut }

SFBool SFFloat SFBool SFRotation SFVec3f SFString SFTime SFBool

set_bind fieldOfView jump orientation position description bindTime isBound

0.785396 TRUE 0 0 1 0 0 0 10 ““

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Sound in VRML 2.0 Definition of Sound Node Sound { exposedField exposedField exposedField exposedField exposedField exposedField exposedField exposedField exposedField field }

SFVec3f SFFloat SFVec3f SFFloat SFFloat SFFloat SFFloat SFFloat SFNode SFBool

direction intensity location maxBack maxFront minBack minFront priority source spatialize

0 0 1 1 0 0 0 10 10 1 1 0 NULL TRUE

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Sound in VRML2.0 Definition of AudioClip Node AudioClip { exposedField exposedField exposedField exposedField exposedField exposedField eventOut eventOut }

SFString description SFBool loop SFFloat pitch SFTime startTime SFTime stopTime MFString url duration_changed isActive

““ FALSE 1.0 0 0 []

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Spatial Sound Pattern in VRML 2.0 Constant intensity location

Linear Attenuation

direction

minBack

minFront maxFront

maxBack

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Internode Communication: Events

eventOut Node A

Node B

Node C eventIn Connection by a ROUTE

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Internode Communication Node Field Classes field

Private node member

exposedField

Public node member

eventIn

Event received by node

eventOut

Event sent by node

set_ _changed

Event received by node Event sent by node

Type and value of events correspond to type and value of node fields.

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Internode Communication Route Syntax DEF T1 Transform { . . . } DEF T2 Transform { . . . } DEF T3 Transform { . . . } . . . ROUTE T1.translation_changed TO T2.set_translation ROUTE T2.translation_changed TO T3.set_translation

T1

T2

T3

translation

translation

translation

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Event Generators: Touch Sensor

= Shapes Sensed

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Event Generators: Touch Sensor TouchSensor { exposedField eventOut eventOut eventOut eventOut eventOut eventOut }

SFBool SFVec3f SFVec3f SFVec2f SFBool SFBool SFTime

enabled TRUE hitNormal_changed hitPoint_changed hitTexCoord_changed isActive isOver touchTime

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Touch Sensor Example Group {

}

children [ DEF TS TouchSensor { } Shape { appearance Appearance { material Material { diffuseColor 0 0.5 0 } } geometry Sphere {} } DEF Highlight DirectionalLight { color 1 0 0 on FALSE } DEF ActiveLight DirectionalLight { color 0 0 1 on FALSE } ] ROUTE TS.isOver TO Highlight.set_on ROUTE TS.isActive TO ActiveLight.set_on

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Touch Sensor Example Group {

}

children [ DEF TS TouchSensor { } Shape { appearance Appearance { material Material { diffuseColor 0 0.5 0 } } geometry Sphere {} } Sound { maxBack 1000 maxFront 1000 source DEF Audio AudioClip { url “horse.wav” } } ] ROUTE TS.touchTime TO Audio.startTime

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Adding Behavior to Objects

TimeSensor

Interpolator

Generates time varying scalar in range [0,1]

Maps [0,1] to field data type values.

[0,1]

General Node

ScalarInterpolator PositionInterpolator OrientationInterpolator CoordinateInterpolator ColorInterpolator

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Time Sensor TimeSensor { exposedField exposedField exposedField exposedField exposedField eventOut eventOut eventOut eventOut }

SFTime SFBool SFBool SFTime SFTime SFTime SFFloat SFBool SFTime

cycleInterval 1 enabled TRUE loop FALSE startTime 0 stopTime 0 cycleTime fraction_changed isActive time

loop=TRUE

loop=FALSE startTime

cycleInterval

stopTime

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Position Interpolator PositionInterpolator eventIn exposedField exposedField eventOut }

{ SFFloat MFFloat MFVec3f SFVec3f

set_fraction key [] keyValue [] value_changed

y

x

Input: [ 0

1]

z

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Position Animation Example Def T Transform { translation 0 5 0 children [ Shape { geometry Cone {} appearance Appearance { material Material { diffuseColor 1 0 0 } } } ] } Def P PositionInterpolator { key [0, 0.5, 1] keyValue [ 0 0 0, 4 0 0, 0 0 0] } Def TS TimeSensor { stopTime -1 loop TRUE } ROUTE TS.fraction_changed TO P.set_fraction ROUTE P.value_changed TO T.set_translation

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Java 3D: Class Hierarchy

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Java 3D: Viewing Classes

Contains information about physical screen Contains most of view state Locates a view within scene

3D version of Abstract Windowing Toolkit

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Java 3D: Sample Code to Build Scene Graph Shape3D myShape1 = new Shape3D(myGeometry1, myAppearance1); Shape3D myShape2 = new Shape3D(myGeometry2, myAppearance2); BranchGroup myBranch = new BranchGroup(); myBranch.addChild(myShape1); myBranch.addChild(myShape2); myBranch.compile(); VirtualUniverse myUniverse = new VirtualUniverse(); Locale myLocale = new Locale(myUniverse); myLocale.addBranchGraph(myBranch);

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Java 3D: Scene Graph Built

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Java 3D; Node Class Hierarchy

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Java 3D “Hello Universe” Program public class HelloUniverse extends Applet { public BranchGroup createSceneGraph() { // Create the root of the branch graph BranchGroup objRoot = new BranchGroup(); // // // //

Create the TransformGroup node and initialize it to the identity. Enable the TRANSFORM_WRITE capability so that our behavior code can modify it at run time. Add it to the root of the subgraph.

TransformGroup objTrans = new TransformGroup(); objTrans.setCapability( TransformGroup.ALLOW_TRANSFORM_WRITE); objRoot.addChild(objTrans); // Create a simple Shape3D node; add it to the scene graph. objTrans.addChild(new ColorCube(0.4)); // Create a new Behavior object that will perform the // desired operation on the specified transform and add // it into the scene graph.

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Java 3D “Hello Universe” Program, contd. Transform3D yAxis = new Transform3D(); Alpha rotationAlpha = new Alpha(-1, 4000); RotationInterpolator rotator = new RotationInterpolator( rotationAlpha, objTrans, yAxis, 0.0f, (float) Math.PI*2.0f); BoundingSphere bounds = new BoundingSphere(new Point3d(0.0,0.0,0.0), 100.0); rotator.setSchedulingBounds(bounds); objRoot.addChild(rotator); // Have Java 3D perform optimizations on this scene graph. objRoot.compile(); return objRoot; } public HelloUniverse() { <set layout of applet, construct canvas3d, add canvas3d> // Create the scene; attach it to the virtual universe BranchGroup scene = createSceneGraph(); SimpleUniverse u = new SimpleUniverse(canvas3d); u.getViewingPlatform().setNominalViewingTransform(); u.addBranchGraph(scene); } }

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