Re: [JAVA3D] Images not stable

[Kelvin Chung]

>Delivered-To: [EMAIL PROTECTED]
>MIME-Version: 1.0
>Date: Fri, 30 Nov 2001 14:59:29 -0800
>From: Kelvin Chung <[EMAIL PROTECTED]>
>Subject: Re: [JAVA3D] Images not stable
>Comments: To: [EMAIL PROTECTED]
>To: [EMAIL PROTECTED]
>
>Hi Guang,
>
>   There is bug in the test program
>(1) In renderRight()
>        gc.clear();
>        gc.setBufferOverride(true);
>        gc.setStereoMode(GraphicsContext3D.STEREO_RIGHT);
>
>    clear() will only clear STEREO_LEFT buffer since
>    it is set before. We should put this after
>    gc.setStereoMode(GraphicsContext3D.STEREO_RIGHT);
>    Best of all, setting GraphicsContext3D.STEREO_BOTH
>    will only invoke clear() once instead of twice.
>(2) There is no need to invoke swap() two times
>    - one for each buffer. Instead swap() will swap
>    both left/right buffer.
>(3) No need to invoke
>         gc.setBufferOverride(true);
>    every frame, only one at the beginning is good
>    enough.
>(4) There is no distingiush between left and right
>     GraphicsContext3D.
>     gc = canvas.getGraphicsContext3D();
>     ...
>     gcLeft = canvas.getGraphicsContext3D();
>     They are the same.
>
>I've modify your program (see attachment)
>and it seems to run fine.
>

I attach the wrong file without setBufferOverride(true)
Here it is again.

- Kelvin


import java.applet.Applet;
import java.awt.BorderLayout;
import java.awt.GraphicsConfiguration;
import java.awt.event.*;
import com.sun.j3d.utils.applet.MainFrame;
import com.sun.j3d.utils.geometry.ColorCube;
import com.sun.j3d.utils.universe.*;
import javax.media.j3d.*;
import javax.vecmath.*;
import java.awt.Dimension;
import java.awt.GraphicsEnvironment;
import javax.media.j3d.PhysicalBody;
import java.awt.Graphics;
import java.awt.Color;
import javax.swing.JPanel;

public class BrTestGratings extends Applet implements Runnable
{
   View view, viewleft;
    private Canvas3D canvas;
    private GraphicsContext3D gc = null, gcLeft=null, gcAnu=null;
    private Geometry grt0, grt1, grt2, grt3;
    private Transform3D cmt = new Transform3D();
    private Transform3D cmtleft=new Transform3D();
            Transform3D temp=new Transform3D();
    RotateGrating grat1=new RotateGrating();
    RotateGrating grat2=new RotateGrating();
    RotateGrating grat3=new RotateGrating();

    private Alpha rotAlpha = new Alpha(-1, 20000);
    Appearance appear=new Appearance();
    Shape3D shape=new Shape3D();
    Graphics grp;
    private SimpleUniverse u = null;
    static Dimension screenSize =java.awt.
                                 Toolkit.
                                 getDefaultToolkit().
                                 getScreenSize();
   Color3f green  = new Color3f(0.0f, 1.0f, 0.0f);
   Color3f blue  = new Color3f(0.0f, 0.0f, 1.0f);
   Color3f red  = new Color3f(1.0f, 0.0f, 0.0f);
   Color3f black  = new Color3f(0.0f, 0.0f, 0.0f);
   int numOfArray = 200;
   double height=1.7, radius=1.2, step=1.0;
    double angle;

    public void renderLeft()
    {
        cmtleft.rotZ(Math.PI/2);
        cmtleft.mul(cmt);
        gc.setModelTransform(cmtleft);
        gc.setStereoMode(GraphicsContext3D.STEREO_LEFT);
        gc.draw(grt1);
        //        gc.draw(grt3);
    }

    public void renderRight()
    {
        gc.setModelTransform(cmt);
        gc.setStereoMode(GraphicsContext3D.STEREO_RIGHT);
        gc.draw(grt2);
        //      gc.draw(grt3);
    }

    public void run()
    {
        grat3.setParameter(numOfArray, height, radius, step, red);
        grt3=grat3.getRotate();
        gc = canvas.getGraphicsContext3D();
        gc.setBufferOverride(true);
        view = canvas.getView();
        grat2.setParameter(numOfArray, height, radius, step, green);
        grt2=grat2.getRotate();
        grat1.setParameter(numOfArray, height, radius, step, red);
        grt1 =grat1.getRotate();

        while (true) {
            gc.setStereoMode(GraphicsContext3D.STEREO_BOTH);
            gc.clear();
            angle = rotAlpha.value() * 2.0*Math.PI;
            cmt.rotY(-angle);
            renderLeft();
            renderRight();
            canvas.swap();
        }
    }

    public BrTestGratings()
    {
    }

    public void init()
    {
        setLayout(new BorderLayout());
        GraphicsConfigTemplate3D g3d = new GraphicsConfigTemplate3D();
        g3d.setStereo(GraphicsConfigTemplate3D.REQUIRED);
        GraphicsConfiguration config = GraphicsEnvironment.
                                   getLocalGraphicsEnvironment().
                                   getDefaultScreenDevice().
                                   getBestConfiguration(g3d);
        canvas = new Canvas3D(config);
        canvas.stopRenderer();
        canvas.setStereoEnable(true);
        canvas.setDoubleBufferEnable(true);
        add("Center", canvas);
        u = new SimpleUniverse(canvas);
        u.getViewingPlatform().setNominalViewingTransform();
        new Thread(this).start();
    }

    public void destroy()
    {
        u.removeAllLocales();
    }

    public static void main(String[] args)
    {
        new MainFrame(new BrTestGratings(),
                          screenSize.width,
                          screenSize.height);
    }
}