exhenge.java

详细介绍Java 3D编程的一本电子书

//
//  CLASS
//    ExHenge - create a stone-henge like (vaguely) mysterious temple thing
//
//  DESCRIPTION
//    This example illustrates the use of a few of Java 3D's lighting
//    types to create atmospheric lighting to make a structure look
//    like it is glowing.  In particular, we build a central emissive
//    dome, unaffected by any lighting.  Surrounding that dome are a
//    series of arches that are lit by a one or more of a point
//    light in the center, directional lights at front-left and
//    back-right, and two ambient lights.  Each of these lights can be
//    turned on and off via menu items.
//
//  SEE ALSO
//    Arch
//    ExAmbientLight
//    ExDirectionalLight
//    ExPointLight
//
//  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 ExHenge
	extends Example
{
	//--------------------------------------------------------------
	//  SCENE CONTENT
	//--------------------------------------------------------------

	//
	//  Nodes (updated via menu)
	//
	private AmbientLight ambient = null;
	private AmbientLight brightAmbient = null;
	private DirectionalLight redDirectional = null;
	private DirectionalLight yellowDirectional = null;
	private PointLight orangePoint = null;

	//
	//  Build scene
	//
	public Group buildScene( )
	{
		// Turn off the example headlight
		setHeadlightEnable( false );

		// Default to walk navigation
		setNavigationType( Walk );

		//
		// Preload the texture images
		//
		if ( debug ) System.err.println( "  textures..." );
		Texture groundTex = null;
		Texture spurTex = null;
		Texture domeTex = null;
		TextureLoader texLoader = null;
		ImageComponent image = null;

		texLoader = new TextureLoader( "mud01.jpg", this );
		image = texLoader.getImage( );
		if ( image == null )
			System.err.println( "Cannot load mud01.jpg texture" );
		else
		{
			groundTex = texLoader.getTexture( );
			groundTex.setBoundaryModeS( Texture.WRAP );
			groundTex.setBoundaryModeT( Texture.WRAP );
			groundTex.setMinFilter( Texture.NICEST );
			groundTex.setMagFilter( Texture.NICEST );
			groundTex.setMipMapMode( Texture.BASE_LEVEL );
			groundTex.setEnable( true );
		}

		texLoader = new TextureLoader( "stonebrk2.jpg", this );
		image = texLoader.getImage( );
		if ( image == null )
			System.err.println( "Cannot load stonebrk2.jpg texture" );
		else
		{
			spurTex = texLoader.getTexture( );
			spurTex.setBoundaryModeS( Texture.WRAP );
			spurTex.setBoundaryModeT( Texture.WRAP );
			spurTex.setMinFilter( Texture.NICEST );
			spurTex.setMagFilter( Texture.NICEST );
			spurTex.setMipMapMode( Texture.BASE_LEVEL );
			spurTex.setEnable( true );
		}

		texLoader = new TextureLoader( "fire.jpg", this );
		image = texLoader.getImage( );
		if ( image == null )
			System.err.println( "Cannot load fire.jpg texture" );
		else
		{
			domeTex = texLoader.getTexture( );
			domeTex.setBoundaryModeS( Texture.WRAP );
			domeTex.setBoundaryModeT( Texture.WRAP );
			domeTex.setMinFilter( Texture.NICEST );
			domeTex.setMagFilter( Texture.NICEST );
			domeTex.setMipMapMode( Texture.BASE_LEVEL );
			domeTex.setEnable( true );
		}


		//
		// Build some shapes we'll need
		//
		if ( debug ) System.err.println( "  flying buttresses..." );

		// Build three types of spurs (flying buttresses)
		Appearance spurApp = new Appearance( );

		Material spurMat = new Material( );
		spurMat.setAmbientColor( 0.6f, 0.6f, 0.6f );
		spurMat.setDiffuseColor( 1.0f, 1.0f, 1.0f );
		spurMat.setSpecularColor( 0.0f, 0.0f, 0.0f );
		spurApp.setMaterial( spurMat );

		Transform3D tr = new Transform3D( );
		tr.setIdentity( );
		tr.setScale( new Vector3d( 1.0, 4.0, 1.0 ) );

		TextureAttributes spurTexAtt = new TextureAttributes( );
		spurTexAtt.setTextureMode( TextureAttributes.MODULATE );
		spurTexAtt.setPerspectiveCorrectionMode(
			TextureAttributes.NICEST );
		spurTexAtt.setTextureTransform( tr );
		spurApp.setTextureAttributes( spurTexAtt );

		if ( spurTex != null )
			spurApp.setTexture( spurTex );

		Arch spur1 = new Arch(
			0.0,          // start Phi
			1.571,        // end Phi
			9,            // nPhi
			-0.0982,      // start Theta
			 0.0982,      // end Theta (11.25 degrees)
			2,            // nTheta
			2.5,          // start radius
			1.0,          // end radius
			0.05,         // start phi thickness
			0.025,        // end phi thickness
			spurApp );    // appearance

		Arch spur2 = new Arch(
			0.0,          // start Phi
			1.571,        // end Phi
			9,            // nPhi
			-0.0982,      // start Theta
			 0.0982,      // end Theta (11.25 degrees)
			2,            // nTheta
			1.5,          // start radius
			2.0,          // end radius
			0.05,         // start phi thickness
			0.025,        // end phi thickness
			spurApp );    // appearance

		Arch spur3 = new Arch(
			0.0,          // start Phi
			1.571,        // end Phi
			9,            // nPhi
			-0.0982,      // start Theta
			 0.0982,      // end Theta (11.25 degrees)
			2,            // nTheta
			1.5,          // start radius
			1.0,          // end radius
			0.05,         // start phi thickness
			0.025,        // end phi thickness
			spurApp );    // appearance

		Arch spur4 = new Arch(
			0.0,          // start Phi
			1.178,        // end Phi
			9,            // nPhi
			-0.0982,      // start Theta
			 0.0982,      // end Theta (11.25 degrees)
			2,            // nTheta
			4.0,          // start radius
			4.0,          // end radius
			0.05,         // start phi thickness
			0.025,        // end phi thickness
			spurApp );    // appearance


		// Put each spur into a shared group so we can instance
		// the spurs multiple times
		SharedGroup spur1Group = new SharedGroup( );
		spur1Group.addChild( spur1 );
		spur1Group.compile( );

		SharedGroup spur2Group = new SharedGroup( );
		spur2Group.addChild( spur2 );
		spur2Group.compile( );

		SharedGroup spur3Group = new SharedGroup( );
		spur3Group.addChild( spur3 );
		spur3Group.compile( );

		SharedGroup spur4Group = new SharedGroup( );
		spur4Group.addChild( spur4 );
		spur4Group.compile( );

		// Build a central dome
		if ( debug ) System.err.println( "  central dome..." );

		Appearance domeApp = new Appearance( );
			// No material needed - we want the dome to glow,
			// so use a REPLACE mode texture only
		TextureAttributes domeTexAtt = new TextureAttributes( );
		domeTexAtt.setTextureMode( TextureAttributes.REPLACE );
		domeTexAtt.setPerspectiveCorrectionMode(
			TextureAttributes.NICEST );
		domeApp.setTextureAttributes( domeTexAtt );

		if ( domeTex != null )
			domeApp.setTexture( domeTex );

		Arch dome = new Arch(
			0.0,          // start Phi
			1.571,        // end Phi
			5,            // nPhi
			0.0,          // start Theta
			2.0*Math.PI,  // end Theta (360 degrees)
			17,           // nTheta
			1.0,          // start radius
			1.0,          // end radius
			0.0,          // start phi thickness
			0.0,          // end phi thickness
			domeApp );    // appearance


		// Build the ground.  Use a trick to get better lighting
		// effects by using an elevation grid.  The idea is this:
		// for interactive graphics systems, such as those
		// controlled by Java3D, lighting effects are computed only
		// at triangle vertexes.  Imagine a big rectangular ground
		// underneath a PointLight (added below).  If the
		// PointLight is above the center of the square, in the real
		// world we'd expect a bright spot below it, fading to
		// darkness at the edges of the square.  Not so in
		// interactive graphics.  Since lighting is only computed
		// at vertexes, and the square's vertexes are each
		// equidistant from a centered PointLight, all four square
		// coordinates get the same brightness.  That brightness
		// is interpolated across the square, giving a *constant*
		// brightness for the entire square!  There is no bright
		// spot under the PointLight.  So, here's the trick:  use
		// more triangles.  Pretty simple.  Split the ground under
		// the PointLight into a grid of smaller squares.  Each
		// smaller square is shaded using light brightness computed
		// at the square's vertexes.  Squares directly under the
		// PointLight get brighter lighting at their vertexes, and
		// thus they are bright.  This gives the desired bright
		// spot under the PointLight.  The more squares we use
		// (a denser grid), the more accurate the bright spot and
		// the smoother the lighting gradation from bright directly
		// under the PointLight, to dark at the distant edges.  Of
		// course, with more squares, we also get more polygons to
		// draw and a performance slow-down.  So there is a
		// tradeoff between lighting quality and drawing speed.
		// For this example, we'll use a coarse mesh of triangles
		// created using an ElevationGrid shape.
		if ( debug ) System.err.println( "  ground..." );

		Appearance groundApp = new Appearance( );

		Material groundMat = new Material( );
		groundMat.setAmbientColor( 0.3f, 0.3f, 0.3f );
		groundMat.setDiffuseColor( 0.7f, 0.7f, 0.7f );
		groundMat.setSpecularColor( 0.0f, 0.0f, 0.0f );
		groundApp.setMaterial( groundMat );

		tr = new Transform3D( );
		tr.setScale( new Vector3d( 8.0, 8.0, 1.0 ) );

		TextureAttributes groundTexAtt = new TextureAttributes( );
		groundTexAtt.setTextureMode( TextureAttributes.MODULATE );
		groundTexAtt.setPerspectiveCorrectionMode(
			TextureAttributes.NICEST );
		groundTexAtt.setTextureTransform( tr );