Working with fog
ExClip.java
//
// CLASS
// ExClip - illustrate use of linear fog with a clip node
//
// LESSON
// Add a LinearFog node to apply fog of varying thickness, then
// add a Clip node to set the back clip plane at the back fog distance.
//
// SEE ALSO
// ExExponentialFog
// ExLinearFog
//
// AUTHOR
// David R. Nadeau / San Diego Supercomputer Center
//
import java.awt.*;
import java.awt.event.*;
import javax.media.j3d.*;
import javax.vecmath.*;
import com.sun.j3d.utils.image.*;
public class ExClip
extends Example
{
//--------------------------------------------------------------
// SCENE CONTENT
//--------------------------------------------------------------
//
// Nodes (updated via menu)
//
private Clip clip = null;
private LinearFog fog = null;
private Background background = null;
//
// Build scene
//
public Group buildScene( )
{
// Get the current color
Color3f color = (Color3f)colors[currentColor].value;
float front = ((Float)fronts[currentFront].value).floatValue( );
float back = ((Float)backs[currentBack].value).floatValue( );
// Turn off the example headlight
setHeadlightEnable( false );
// Default to walk navigation
setNavigationType( Walk );
// Create the scene group
Group scene = new Group( );
// BEGIN EXAMPLE TOPIC
// Create influencing bounds
BoundingSphere worldBounds = new BoundingSphere(
new Point3d( 0.0, 0.0, 0.0 ), // Center
1000.0 ); // Extent
// Set the fog color, front & back distances, and
// its influencing bounds
fog = new LinearFog( );
fog.setColor( color );
fog.setFrontDistance( front );
fog.setBackDistance( back );
fog.setCapability( Fog.ALLOW_COLOR_WRITE );
fog.setCapability( LinearFog.ALLOW_DISTANCE_WRITE );
fog.setInfluencingBounds( worldBounds );
scene.addChild( fog );
// Add a clip node with it's clip distance (back
// distance) set to the fog's back distance. This
// insures that shapes are clipped off, and not drawn,
// from the fog back (maximum density) onwards into
// the distance.
clip = new Clip( );
clip.setBackDistance( back );
clip.setCapability( Clip.ALLOW_BACK_DISTANCE_WRITE );
clip.setApplicationBounds( worldBounds );
scene.addChild( clip );
// END EXAMPLE TOPIC
// Set the background color and its application bounds
// Usually, the background color should match the fog color
// or the results look odd.
background = new Background( );
background.setColor( color );
background.setApplicationBounds( worldBounds );
background.setCapability( Background.ALLOW_COLOR_WRITE );
scene.addChild( background );
// Build foreground geometry
scene.addChild( new ColumnScene( this ) );
return scene;
}
//--------------------------------------------------------------
// USER INTERFACE
//--------------------------------------------------------------
//
// Main
//
public static void main( String[] args )
{
ExClip ex = new ExClip( );
ex.initialize( args );
ex.buildUniverse( );
ex.showFrame( );
}
// Coupled background and fog color
private boolean coupledBackgroundOnOff = true;
private CheckboxMenuItem coupledBackgroundOnOffMenu = null;
// Color menu choices
private NameValue[] colors = {
new NameValue( "White", White ),
new NameValue( "Gray", Gray ),
new NameValue( "Dark Gray", DarkGray ),
new NameValue( "Black", Black ),
new NameValue( "Red", Red ),
new NameValue( "Dark Red", DarkRed ),
new NameValue( "Green", Green ),
new NameValue( "Dark Green", DarkGreen ),
new NameValue( "Blue", Blue ),
new NameValue( "Dark Blue", DarkBlue ),
};
private int currentColor = 0;
private int currentBackgroundColor = currentColor;
private CheckboxMenu colorMenu;
private CheckboxMenu backgroundColorMenu;
// Front distance menu choices
private NameValue[] fronts = {
new NameValue( "At front (0.0)", new Float( 0.0f ) ),
new NameValue( "Near distance (2.0)", new Float( 2.0f ) ),
new NameValue( "Mid distance (12.0)", new Float( 12.0f ) ),
new NameValue( "Far distance (22.0)", new Float( 22.0f ) ),
};
private int currentFront = 0;
private CheckboxMenu frontMenu;
// Back distance menu choices
private NameValue[] backs = {
new NameValue( "At front (0.0)", new Float( 0.0f ) ),
new NameValue( "Near distance (2.0)", new Float( 2.0f ) ),
new NameValue( "Mid distance (12.0)", new Float( 12.0f ) ),
new NameValue( "Far distance (22.0)", new Float( 22.0f ) ),
};
private int currentBack = 3;
private CheckboxMenu backMenu;
// Coupled clip and fog back distance
private boolean coupledClipBackOnOff = true;
private CheckboxMenuItem coupledClipBackOnOffMenu = null;
// Clip back distance menu choices
private NameValue[] clipBacks = {
new NameValue( "At front (0.0)", new Float( 0.0f ) ),
new NameValue( "Near distance (2.0)", new Float( 2.0f ) ),
new NameValue( "Mid distance (12.0)", new Float( 12.0f ) ),
new NameValue( "Far distance (22.0)", new Float( 22.0f ) ),
};
private int currentClipBack = 3;
private CheckboxMenu clipBackMenu;
//
// Initialize the GUI (application and applet)
//
public void initialize( String[] args )
{
// Initialize the window, menubar, etc.
super.initialize( args );
exampleFrame.setTitle( "Java 3D Clip Example" );
//
// Add a menubar menu to change node parameters
// Coupled background color
// Background color -->
// Fog color -->
// Fog front distance -->
// Fog back distance -->
// Coupled clip back distance
// Clip back distance -->
//
Menu m = new Menu( "Fog and Clip" );
coupledBackgroundOnOffMenu = new CheckboxMenuItem(
"Couple background color", coupledBackgroundOnOff );
coupledBackgroundOnOffMenu.addItemListener( this );
m.add( coupledBackgroundOnOffMenu );
backgroundColorMenu = new CheckboxMenu( "Background color", colors,
currentBackgroundColor, this );
m.add( backgroundColorMenu );
backgroundColorMenu.setEnabled( !coupledBackgroundOnOff );
colorMenu = new CheckboxMenu( "Fog color", colors,
currentColor, this );
m.add( colorMenu );
frontMenu = new CheckboxMenu( "Fog front distance", fronts,
currentFront, this );
m.add( frontMenu );
backMenu = new CheckboxMenu( "Fog back distance", backs,
currentBack, this );
m.add( backMenu );
coupledClipBackOnOffMenu = new CheckboxMenuItem(
"Couple clip back distance", coupledClipBackOnOff );
coupledClipBackOnOffMenu.addItemListener( this );
m.add( coupledClipBackOnOffMenu );
clipBackMenu = new CheckboxMenu( "Clip back distance", clipBacks,
currentClipBack, this );
clipBackMenu.setEnabled( !coupledClipBackOnOff );
m.add( clipBackMenu );
exampleMenuBar.add( m );
}
//
// Handle checkboxes and menu choices
//
public void checkboxChanged( CheckboxMenu menu, int check )
{
if ( menu == backgroundColorMenu )
{
// Change the background color
currentBackgroundColor = check;
Color3f color = (Color3f)colors[check].value;
background.setColor( color );
return;
}
if ( menu == colorMenu )
{
// Change the fog color
currentColor = check;
Color3f color = (Color3f)colors[check].value;
fog.setColor( color );
// If background is coupled, set the background color
if ( coupledBackgroundOnOff )
{
currentBackgroundColor = currentColor;
backgroundColorMenu.setCurrent( check );
background.setColor( color );
}
return;
}
if ( menu == frontMenu )
{
// Change the fog front distance
currentFront = check;
float front = ((Float)fronts[currentFront].value).floatValue( );
fog.setFrontDistance( front );
return;
}
if ( menu == backMenu )
{
// Change the fog back distance
currentBack = check;
float back = ((Float)backs[currentBack].value).floatValue( );
fog.setBackDistance( back );
if ( coupledClipBackOnOff )
{
float clipBack = ((Float)clipBacks[currentClipBack].value).floatValue( );
clipBackMenu.setCurrent( check );
clip.setBackDistance( clipBack );
}
return;
}
if ( menu == clipBackMenu )
{
// Change the clip back distance
currentClipBack = check;
float clipBack = ((Float)clipBacks[currentClipBack].value).floatValue( );
clip.setBackDistance( clipBack );
return;
}
// Handle all other checkboxes
super.checkboxChanged( menu, check );
}
public void itemStateChanged( ItemEvent event )
{
Object src = event.getSource( );
// Check if it is the coupled background choice
if ( src == coupledBackgroundOnOffMenu )
{
coupledBackgroundOnOff = coupledBackgroundOnOffMenu.getState( );
if ( coupledBackgroundOnOff )
{
currentBackgroundColor = currentColor;
backgroundColorMenu.setCurrent( currentColor );
Color3f color = (Color3f)colors[currentColor].value;
background.setColor( color );
backgroundColorMenu.setEnabled( false );
}
else
{
backgroundColorMenu.setEnabled( true );
}
}
// Check if it is the coupled clip back distance choice
if ( src == coupledClipBackOnOffMenu )
{
coupledClipBackOnOff = coupledClipBackOnOffMenu.getState( );
if ( coupledClipBackOnOff )
{
currentClipBack = currentBack;
clipBackMenu.setCurrent( currentClipBack );
float clipBack = ((Float)clipBacks[currentClipBack].value).floatValue( );
clip.setBackDistance( clipBack );
clipBackMenu.setEnabled( false );
}
else
{
clipBackMenu.setEnabled( true );
}
}
// Handle all other checkboxes
super.itemStateChanged( event );
}
}