ok.Let me try that.

May be right. But what I had observed one more thing that the source mesh is having only 10 vertices.So I need to pull only those two right vertices of the box on the X axis.The current logic of the apply() method is updating all vertices and applying to all vertices of destination mesh.But from the vertices list of he source mesh, can I know which are those two right vertices of the box that are to be stretched? .Please correct me.

One more quick clarification here.When  I press A key, it stretches its both vertices diagonally.Is this the expected behaviour or can I pull along it on only x-axis? Is there any other standard algorithms I have to use for this?

@EgonOlsen. Thanks.It really helped. .I know my level of understanding is very little here.Now it works.

Sure. I am pasting the code here.What it does is when you move mouse left or righ , the shapes on the screen rotates.The red color box is the candidate here.This one is not getting stretched on x-axis when I press 'A' key on keyboard.


/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/

package org.me.home;

import android.app.Activity;
import android.opengl.GLSurfaceView;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.MotionEvent;
import com.threed.jpct.Camera;
import com.threed.jpct.FrameBuffer;
import com.threed.jpct.GenericVertexController;
import com.threed.jpct.IVertexController;
import com.threed.jpct.Light;
import com.threed.jpct.Logger;
import com.threed.jpct.Mesh;
import com.threed.jpct.Object3D;
import com.threed.jpct.Primitives;
import com.threed.jpct.RGBColor;
import com.threed.jpct.SimpleVector;
import com.threed.jpct.World;
import com.threed.jpct.util.MemoryHelper;
import java.lang.reflect.Field;
import javax.microedition.khronos.egl.EGL10;
import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.egl.EGLDisplay;
import javax.microedition.khronos.opengles.GL10;

/**
*
* @author Unni Vemanchery Mana
*/

public class MainActivity extends Activity {

// Used to handle pause and resume...
private static MainActivity master = null;

private GLSurfaceView mGLView;
private MyRenderer renderer = null;
private FrameBuffer fb = null;
private World world = null;
private RGBColor back = new RGBColor(50, 50, 100);

private float touchTurn = 0;
private float touchTurnUp = 0;

private float xpos = -1;
private float ypos = -1;

private Object3D cube = null;
        private Object3D box = null;
        private Object3D newbox = null;
        private Object3D line3d = null;

       
private int fps = 0;

private Light sun = null;

        private float xDelta = 1.5f;
        private float yDelta = 0;
        private float zDelta = 0;
        private int counter = 0;
       
    @Override
protected void onCreate(Bundle savedInstanceState) {

Logger.log("onCreate");

if (master != null) {
copy(master);
}

super.onCreate(savedInstanceState);
mGLView = new GLSurfaceView(getApplication());

mGLView.setEGLConfigChooser(new GLSurfaceView.EGLConfigChooser() {
public EGLConfig chooseConfig(EGL10 egl, EGLDisplay display) {
// Ensure that we get a 16bit framebuffer. Otherwise, we'll fall
// back to Pixelflinger on some device (read: Samsung I7500)
int[] attributes = new int[] { EGL10.EGL_DEPTH_SIZE, 16, EGL10.EGL_NONE };
EGLConfig[] configs = new EGLConfig[1];
int[] result = new int[1];
egl.eglChooseConfig(display, attributes, configs, 1, result);
return configs[0];
}
});

renderer = new MyRenderer();
mGLView.setRenderer(renderer);
setContentView(mGLView);
}

@Override
protected void onPause() {
super.onPause();
mGLView.onPause();
}

@Override
protected void onResume() {
super.onResume();
mGLView.onResume();
}

@Override
protected void onStop() {
super.onStop();
}

private void copy(Object src) {
try {
Logger.log("Copying data from master Activity!");
Field[] fs = src.getClass().getDeclaredFields();
for (Field f : fs) {
f.setAccessible(true);
f.set(this, f.get(src));
}
} catch (Exception e) {
throw new RuntimeException(e);
}
}

    @Override
public boolean onTouchEvent(MotionEvent me) {

if (me.getAction() == MotionEvent.ACTION_DOWN) {
xpos = me.getX();
ypos = me.getY();
return true;
}

if (me.getAction() == MotionEvent.ACTION_UP) {
xpos = -1;
ypos = -1;
touchTurn = 0;
touchTurnUp = 0;
return true;
}

if (me.getAction() == MotionEvent.ACTION_MOVE) {
float xd = me.getX() - xpos;
float yd = me.getY() - ypos;

xpos = me.getX();
ypos = me.getY();

touchTurn = xd / -100f;
touchTurnUp = yd / -100f;
return true;
}

try {
Thread.sleep(15);
} catch (Exception e) {
// No need for this...
}

return super.onTouchEvent(me);
}

    @Override
        public boolean onKeyDown(int keyCode, KeyEvent msg) {
          if( keyCode == KeyEvent.KEYCODE_A ) {
              System.out.println(" total angle swept " + box.getTransformedCenter().calcAngle(box.getXAxis()) );
              Mesh mesh = box.getMesh();
              VertexController vc = new VertexController(mesh);
              mesh.setVertexController(vc,true);
              mesh.applyVertexController();
              xDelta+=1.5f;
              return true;
          }
         return true;
        }
     


private Object3D createLine (SimpleVector pointA, SimpleVector pointB, float width, String textureName)
{
    Object3D line = new Object3D( 8 );
    float offset = width / 2.0f;
    // Quad A:
    line.addTriangle( new SimpleVector( pointA.x, pointA.y - offset, pointA.z ), 0, 0,
                     new SimpleVector( pointA.x, pointA.y + offset, pointA.z ), 0, 1,
                     new SimpleVector( pointB.x, pointB.y + offset, pointB.z ), 1, 1
                     );
    line.addTriangle( new SimpleVector( pointB.x, pointB.y + offset, pointB.z ), 0, 0,
                     new SimpleVector( pointB.x, pointB.y - offset, pointB.z ), 0, 1,
                     new SimpleVector( pointA.x, pointA.y - offset, pointA.z ), 1, 1
                     );
    // Quad A, back-face:
    line.addTriangle( new SimpleVector( pointB.x, pointB.y - offset, pointB.z ), 0, 0,
                     new SimpleVector( pointB.x, pointB.y + offset, pointB.z ), 0, 1,
                     new SimpleVector( pointA.x, pointA.y + offset, pointA.z ), 1, 1
                     );
    line.addTriangle( new SimpleVector( pointA.x, pointA.y + offset, pointA.z ), 0, 0,
                     new SimpleVector( pointA.x, pointA.y - offset, pointA.z ), 0, 1,
                     new SimpleVector( pointB.x, pointB.y - offset, pointB.z ), 1, 1
                     );
    // Quad B:
    line.addTriangle( new SimpleVector( pointA.x, pointA.y, pointA.z + offset ), 0, 0,
                     new SimpleVector( pointA.x, pointA.y, pointA.z - offset ), 0, 1,
                     new SimpleVector( pointB.x, pointB.y, pointB.z - offset ), 1, 1
                     );
    line.addTriangle( new SimpleVector( pointB.x, pointB.y, pointB.z - offset ), 0, 0,
                     new SimpleVector( pointB.x, pointB.y, pointB.z + offset ), 0, 1,
                     new SimpleVector( pointA.x, pointA.y, pointA.z + offset ), 1, 1
                     );

    // Quad B, back-face:
    line.addTriangle( new SimpleVector( pointB.x, pointB.y, pointB.z + offset ), 0, 0,
                     new SimpleVector( pointB.x, pointB.y, pointB.z - offset ), 0, 1,
                     new SimpleVector( pointA.x, pointA.y, pointA.z - offset ), 1, 1
                     );
    line.addTriangle( new SimpleVector( pointA.x, pointA.y, pointA.z - offset ), 0, 0,
                     new SimpleVector( pointA.x, pointA.y, pointA.z + offset ), 0, 1,
                     new SimpleVector( pointB.x, pointB.y, pointB.z + offset ), 1, 1
                     );
 

    // If you don't want the line to react to lighting:
    line.setLighting( Object3D.LIGHTING_NO_LIGHTS );
    line.setAdditionalColor( RGBColor.WHITE );

    // done
    return line;
}

protected boolean isFullscreenOpaque() {
return true;
}

class MyRenderer implements GLSurfaceView.Renderer {

private long time = System.currentTimeMillis();

public MyRenderer() {
}

public void onSurfaceChanged(GL10 gl, int w, int h) {
if (fb != null) {
fb.dispose();
}
fb = new FrameBuffer(gl, w, h);

if (master == null) {

world = new World();
world.setAmbientLight(20, 20, 20);

sun = new Light(world);
sun.setIntensity(250, 250, 250);

// Create a texture out of the icon...:-)
//Texture texture = new Texture(BitmapHelper.rescale(BitmapHelper.convert(getResources().getDrawable(R.drawable.icon)), 64, 64));
//TextureManager.getInstance().addTexture("texture", texture);

cube = Primitives.getCube(1);
//cube.calcTextureWrapSpherical();
//cube.setTexture("texture");
//cube.strip();
//cube.build();

                                box = Primitives.getBox(1.5f, 0.75f);
                                box.setAdditionalColor(RGBColor.RED);
                              //  box.setTransparency(0);

                                box.translate(-10, 10, 0);
                                box.translateMesh();
                              //  box.strip();
                                System.out.println(" first box center "+ box.getOrigin());

                                // adding one more cube
                                newbox = Primitives.getBox(1.5f, 0.70f);
                                newbox.setAdditionalColor(RGBColor.RED);
                               // newbox.setTransparency(0);
                                newbox.translate((-10.0f + 1.0f), 10.0f, -1.0f);
                                newbox.translateMesh();
                                newbox.strip();


world.addObject(cube);
                                world.addObject(box);
                                world.addObject(newbox);


                                line3d = createLine(new SimpleVector(5,0,0), new SimpleVector(5,10,0), 2, "");
                                line3d.translate(5, 0, 0);
                                line3d.translateMesh();

                                world.addObject(line3d);

Camera cam = world.getCamera();
cam.moveCamera(Camera.CAMERA_MOVEOUT, 50);
cam.lookAt(cube.getTransformedCenter());

SimpleVector sv = new SimpleVector();
sv.set(cube.getTransformedCenter());
sv.y -= 100;
sv.z -= 100;
sun.setPosition(sv);
MemoryHelper.compact();

if (master == null) {
Logger.log("Saving master Activity!");
master = MainActivity.this;
}
}
}

public void onSurfaceCreated(GL10 gl, EGLConfig config) {
}

public void onDrawFrame(GL10 gl) {
if (touchTurn != 0) {
    cube.rotateY(touchTurn);
                            box.rotateY(touchTurn) ;
                            line3d.rotateY(touchTurn);
    touchTurn = 0;
                            yDelta +=0.02f;
}

if (touchTurnUp != 0) {
    cube.rotateX( touchTurnUp );
    touchTurnUp = 0;
}

fb.clear(back);
world.renderScene(fb);
world.draw(fb);
fb.display();

if (System.currentTimeMillis() - time >= 1000) {
//Logger.log(fps + "fps");
fps = 0;
time = System.currentTimeMillis();
}
fps++;
}
}

      class VertexController extends GenericVertexController {

        public VertexController( Mesh toCheck ) {
   //  super.init(toCheck, true);
        }
        public void apply() {
            SimpleVector[] vertices = getSourceMesh();
    SimpleVector[] destination = getDestinationMesh();
            for (int i = 0; i < vertices.length; i++){
                System.out.println("before vertices[i].x "+vertices[i].x);
             //vertices[i].x *= vertices[i].x * 5;
             System.out.println("after vertices[i].x "+vertices[i].x);
     destination[i].x+=destination[i].x + xDelta;
    }
   this.updateMesh();
        }
      }

}



That is ok ...@EgonOlsen.No probs.. .
But even if I commented that line , what happens is that the box size is not getting affected on x-axis when I press some key.Can I extend a box on its x-axis so that the box slowly turns to be a 3d rectangle?

still the same error persists.In the code, I am creating new instances of VertexController every time.I have modified the code also.

@Override
        public boolean onKeyDown(int keyCode, KeyEvent msg) {
          if( keyCode == KeyEvent.KEYCODE_A ) {
              System.out.println(" total angle swept " + box.getTransformedCenter().calcAngle(box.getXAxis()) );
              Mesh mesh = box.getMesh();
              VertexController vc = new VertexController(mesh);
              mesh.setVertexController(vc,true);
              mesh.applyVertexController();
              xDelta+=1.5f;
              return true;
          }
         return true;
        }

Not able to figure it out. Do I need to make the box object itself local

I resolved this error by commenting the constructor call in the VertexController.This is the modified code.

      class VertexController extends GenericVertexController {

        public VertexController( Object3D toCheck ) {
     // super.init(toCheck.getMesh(), true);
        }
        public void apply() {
            SimpleVector[] vertices   = getSourceMesh();
    SimpleVector[] destination = getDestinationMesh();
            for (int i = 0; i < vertices.length; i++){
             vertices[i].x *= vertices[i].x * 5;
     destination[i].x = vertices[i].x;
    }
   //this.updateMesh();
        }
      }
===================
        public boolean onKeyDown(int keyCode, KeyEvent msg) {
          if( keyCode == KeyEvent.KEYCODE_A ) {
              System.out.println(" total angle swept " + box.getTransformedCenter().calcAngle(box.getXAxis()) );
              //world.removeObject(box);
              //box = createBox(xDelta, 0.75f);
              //box.setAdditionalColor(RGBColor.WHITE);
              //box.translate(-10, 10, 0);
              //world.addObject( box );
              //world.buildAllObjects();
              VertexController vc = new VertexController(box);
              Mesh mesh = box.getMesh();
              mesh.setVertexController(vc, true);
              mesh.applyVertexController();
              xDelta+=1.5f;
              return true;
          }
         return true;
        }


After making these changes , I am able to run the application. But when  I press the A key, the box size is not increasing on x-axis.Is there anything I missed here?

I have modified  the code like this:

public boolean onKeyDown(int keyCode, KeyEvent msg) {
          if( keyCode == KeyEvent.KEYCODE_A ) {
              System.out.println(" total angle swept " + box.getTransformedCenter().calcAngle(box.getXAxis()) );
              VertexController vc = new VertexController(box);
              box.getMesh().setVertexController(vc, IVertexController.PRESERVE_SOURCE_MESH);
              //vc.setScale(box.getTransformedCenter());
              //vc.apply();
              xDelta+=1.5f;
              return true;
          }
         return true;
        }
===============
  class VertexController extends GenericVertexController {

        public VertexController( Object3D toCheck ) {
      super.init(toCheck.getMesh(), true);
        }
       
        public void apply() {
            SimpleVector[] vertices   = getSourceMesh();
    SimpleVector[] destination = getDestinationMesh();
            for (int i = 0; i < vertices.length; i++){
    //vertices[i].x *= scale.x;
            // System.out.println(" scale.x " + scale.x);
             vertices[i].x *= vertices[i].x * 5;
     //vertices[i].y *= vertices[i].y * 3;
    //vertices[i].z *= scale.z * 5;

    destination[i].x = vertices[i].x;
   // destination[i].y = vertices[i].y;
    //destination[i].z = vertices[i].z;
    }
    this.updateMesh();
        }

I moved the logic inside the apply method as you told.But I am getting the following error:
09-20 14:52:37.761: ERROR/AndroidRuntime(1188): java.lang.RuntimeException: [ 1316510557744 ] - ERROR: This instance has already been assigned to another Mesh!

what exactly the strip() method tries to do here?

I am getting null pointer exception during runtime.Let me paste the code snippet that I have used and exception details.

/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/

package org.me.home;

import android.app.Activity;
import android.opengl.GLSurfaceView;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.MotionEvent;
import com.threed.jpct.Camera;
import com.threed.jpct.FrameBuffer;
import com.threed.jpct.GenericVertexController;
import com.threed.jpct.Light;
import com.threed.jpct.Logger;
import com.threed.jpct.Object3D;
import com.threed.jpct.Primitives;
import com.threed.jpct.RGBColor;
import com.threed.jpct.SimpleVector;
import com.threed.jpct.World;
import com.threed.jpct.util.MemoryHelper;
import java.lang.reflect.Field;
import javax.microedition.khronos.egl.EGL10;
import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.egl.EGLDisplay;
import javax.microedition.khronos.opengles.GL10;

/**
*
* @author Unni Vemanchery Mana
*/

public class MainActivity extends Activity {

// Used to handle pause and resume...
private static MainActivity master = null;

private GLSurfaceView mGLView;
private MyRenderer renderer = null;
private FrameBuffer fb = null;
private World world = null;
private RGBColor back = new RGBColor(50, 50, 100);

private float touchTurn = 0;
private float touchTurnUp = 0;

private float xpos = -1;
private float ypos = -1;

private Object3D cube = null;
        private Object3D box = null;
        private Object3D newbox = null;
        private Object3D line3d = null;

       
private int fps = 0;

private Light sun = null;

        private float xDelta = 1.5f;
        private float yDelta = 0;
        private float zDelta = 0;
        private int counter = 0;
       
       
    @Override
protected void onCreate(Bundle savedInstanceState) {

Logger.log("onCreate");

if (master != null) {
copy(master);
}

super.onCreate(savedInstanceState);
mGLView = new GLSurfaceView(getApplication());

mGLView.setEGLConfigChooser(new GLSurfaceView.EGLConfigChooser() {
public EGLConfig chooseConfig(EGL10 egl, EGLDisplay display) {
// Ensure that we get a 16bit framebuffer. Otherwise, we'll fall
// back to Pixelflinger on some device (read: Samsung I7500)
int[] attributes = new int[] { EGL10.EGL_DEPTH_SIZE, 16, EGL10.EGL_NONE };
EGLConfig[] configs = new EGLConfig[1];
int[] result = new int[1];
egl.eglChooseConfig(display, attributes, configs, 1, result);
return configs[0];
}
});

renderer = new MyRenderer();
mGLView.setRenderer(renderer);
setContentView(mGLView);
}

@Override
protected void onPause() {
super.onPause();
mGLView.onPause();
}

@Override
protected void onResume() {
super.onResume();
mGLView.onResume();
}

@Override
protected void onStop() {
super.onStop();
}

private void copy(Object src) {
try {
Logger.log("Copying data from master Activity!");
Field[] fs = src.getClass().getDeclaredFields();
for (Field f : fs) {
f.setAccessible(true);
f.set(this, f.get(src));
}
} catch (Exception e) {
throw new RuntimeException(e);
}
}

    @Override
public boolean onTouchEvent(MotionEvent me) {

if (me.getAction() == MotionEvent.ACTION_DOWN) {
xpos = me.getX();
ypos = me.getY();
return true;
}

if (me.getAction() == MotionEvent.ACTION_UP) {
xpos = -1;
ypos = -1;
touchTurn = 0;
touchTurnUp = 0;
return true;
}

if (me.getAction() == MotionEvent.ACTION_MOVE) {
float xd = me.getX() - xpos;
float yd = me.getY() - ypos;

xpos = me.getX();
ypos = me.getY();

touchTurn = xd / -100f;
touchTurnUp = yd / -100f;
return true;
}

try {
Thread.sleep(15);
} catch (Exception e) {
// No need for this...
}

return super.onTouchEvent(me);
}

    @Override
        public boolean onKeyDown(int keyCode, KeyEvent msg) {
          if( keyCode == KeyEvent.KEYCODE_A ) {
              System.out.println(" total angle swept " + box.getTransformedCenter().calcAngle(box.getXAxis()) );
              //world.removeObject(box);
              //box = createBox(xDelta, 0.75f);
              //box.setAdditionalColor(RGBColor.WHITE);
              //box.translate(-10, 10, 0);
              //world.addObject( box );
              //world.buildAllObjects();
              VertexController vc = new VertexController(box);
              vc.scale(box.getTransformedCenter());
              xDelta+=1.5f;
              return true;
          }
         return true;
        }

        private Object3D drawRectangle() {
            Object3D rectangle = new Object3D(20);
            for (int y=0; y < 10; y++) {
        float fY = y / -10f;
        rectangle.addTriangle(new SimpleVector(-1, fY, 1), 0, 0,
                        new SimpleVector(-1, fY, -1), 0, 1,
                        new SimpleVector(1, fY, -1), 1, 1);
        rectangle.addTriangle(new SimpleVector(1, fY, -1), 1, 1,
                        new SimpleVector(1, fY, 1), 1, 0,
                        new SimpleVector(-1, fY, 1), 0, 0);
    }
     return rectangle;
  }

private Object3D createBox(float width, float height) {
     return Primitives.getBox(width, height);
}

private Object3D createLine (SimpleVector pointA, SimpleVector pointB, float width, String textureName)
{
    Object3D line = new Object3D( 8 );
    float offset = width / 2.0f;
    // Quad A:
    line.addTriangle( new SimpleVector( pointA.x, pointA.y - offset, pointA.z ), 0, 0,
                     new SimpleVector( pointA.x, pointA.y + offset, pointA.z ), 0, 1,
                     new SimpleVector( pointB.x, pointB.y + offset, pointB.z ), 1, 1
                     );
    line.addTriangle( new SimpleVector( pointB.x, pointB.y + offset, pointB.z ), 0, 0,
                     new SimpleVector( pointB.x, pointB.y - offset, pointB.z ), 0, 1,
                     new SimpleVector( pointA.x, pointA.y - offset, pointA.z ), 1, 1
                     );
    // Quad A, back-face:
    line.addTriangle( new SimpleVector( pointB.x, pointB.y - offset, pointB.z ), 0, 0,
                     new SimpleVector( pointB.x, pointB.y + offset, pointB.z ), 0, 1,
                     new SimpleVector( pointA.x, pointA.y + offset, pointA.z ), 1, 1
                     );
    line.addTriangle( new SimpleVector( pointA.x, pointA.y + offset, pointA.z ), 0, 0,
                     new SimpleVector( pointA.x, pointA.y - offset, pointA.z ), 0, 1,
                     new SimpleVector( pointB.x, pointB.y - offset, pointB.z ), 1, 1
                     );
    // Quad B:
    line.addTriangle( new SimpleVector( pointA.x, pointA.y, pointA.z + offset ), 0, 0,
                     new SimpleVector( pointA.x, pointA.y, pointA.z - offset ), 0, 1,
                     new SimpleVector( pointB.x, pointB.y, pointB.z - offset ), 1, 1
                     );
    line.addTriangle( new SimpleVector( pointB.x, pointB.y, pointB.z - offset ), 0, 0,
                     new SimpleVector( pointB.x, pointB.y, pointB.z + offset ), 0, 1,
                     new SimpleVector( pointA.x, pointA.y, pointA.z + offset ), 1, 1
                     );

    // Quad B, back-face:
    line.addTriangle( new SimpleVector( pointB.x, pointB.y, pointB.z + offset ), 0, 0,
                     new SimpleVector( pointB.x, pointB.y, pointB.z - offset ), 0, 1,
                     new SimpleVector( pointA.x, pointA.y, pointA.z - offset ), 1, 1
                     );
    line.addTriangle( new SimpleVector( pointA.x, pointA.y, pointA.z - offset ), 0, 0,
                     new SimpleVector( pointA.x, pointA.y, pointA.z + offset ), 0, 1,
                     new SimpleVector( pointB.x, pointB.y, pointB.z + offset ), 1, 1
                     );
 

    // If you don't want the line to react to lighting:
    line.setLighting( Object3D.LIGHTING_NO_LIGHTS );
    line.setAdditionalColor( RGBColor.WHITE );

    // done
    return line;
}

protected boolean isFullscreenOpaque() {
return true;
}

class MyRenderer implements GLSurfaceView.Renderer {

private long time = System.currentTimeMillis();

public MyRenderer() {
}

public void onSurfaceChanged(GL10 gl, int w, int h) {
if (fb != null) {
fb.dispose();
}
fb = new FrameBuffer(gl, w, h);

if (master == null) {

world = new World();
world.setAmbientLight(20, 20, 20);

sun = new Light(world);
sun.setIntensity(250, 250, 250);

// Create a texture out of the icon...:-)
//Texture texture = new Texture(BitmapHelper.rescale(BitmapHelper.convert(getResources().getDrawable(R.drawable.icon)), 64, 64));
//TextureManager.getInstance().addTexture("texture", texture);

cube = Primitives.getCube(1);
//cube.calcTextureWrapSpherical();
//cube.setTexture("texture");
//cube.strip();
//cube.build();

                                box = Primitives.getBox(1.5f, 0.75f);
                                box.setAdditionalColor(RGBColor.RED);
                              //  box.setTransparency(0);

                                box.translate(-10, 10, 0);
                                box.translateMesh();
                                box.strip();
                                System.out.println(" first box center "+ box.getOrigin());

                                // adding one more cube
                                newbox = Primitives.getBox(1.5f, 0.70f);
                                newbox.setAdditionalColor(RGBColor.RED);
                               // newbox.setTransparency(0);
                                newbox.translate((-10.0f + 1.0f), 10.0f, -1.0f);
                                newbox.translateMesh();
                                newbox.strip();


world.addObject(cube);
                                world.addObject(box);
                                world.addObject(newbox);


                                line3d = createLine(new SimpleVector(5,0,0), new SimpleVector(5,10,0), 2, "");
                                line3d.translate(5, 0, 0);
                                line3d.translateMesh();

                                world.addObject(line3d);

Camera cam = world.getCamera();
cam.moveCamera(Camera.CAMERA_MOVEOUT, 50);
cam.lookAt(cube.getTransformedCenter());

SimpleVector sv = new SimpleVector();
sv.set(cube.getTransformedCenter());
sv.y -= 100;
sv.z -= 100;
sun.setPosition(sv);
MemoryHelper.compact();

if (master == null) {
Logger.log("Saving master Activity!");
master = MainActivity.this;
}
}
}

public void onSurfaceCreated(GL10 gl, EGLConfig config) {
}

public void onDrawFrame(GL10 gl) {
if (touchTurn != 0) {
    cube.rotateY(touchTurn);
                            box.rotateY(touchTurn) ;
                            line3d.rotateY(touchTurn);
    touchTurn = 0;
                            yDelta +=0.02f;
}

if (touchTurnUp != 0) {
    cube.rotateX( touchTurnUp );
    touchTurnUp = 0;
}

fb.clear(back);
world.renderScene(fb);
world.draw(fb);
fb.display();

if (System.currentTimeMillis() - time >= 1000) {
//Logger.log(fps + "fps");
fps = 0;
time = System.currentTimeMillis();
}
fps++;
}
}

      class VertexController extends GenericVertexController {

        public VertexController( Object3D toCheck ) {
            if(toCheck.getMesh() == null )
              System.out.println(" ....It is null.... ");
            else
                System.out.println(" ....It is NOT null.... ");
      super.init(toCheck.getMesh(), true);
        }

        public void scale( SimpleVector scale ){
            SimpleVector[] vertices   = getSourceMesh();
    SimpleVector[] destination = getDestinationMesh();
            for (int i = 0; i < vertices.length; i++){
    //vertices[i].x *= scale.x;
              vertices[i].x += scale.x;
    //vertices[i].y *= scale.y;
    //vertices[i].z *= scale.z;
    destination[i].x = vertices[i].x;
    destination[i].y = vertices[i].y;
    destination[i].z = vertices[i].z;
    }
    this.updateMesh();
        }

        public void apply() {
        }
         
      }

}

=============================
  Exception details:
09-19 18:30:50.774: ERROR/AndroidRuntime(299): FATAL EXCEPTION: main
09-19 18:30:50.774: ERROR/AndroidRuntime(299): java.lang.NullPointerException
09-19 18:30:50.774: ERROR/AndroidRuntime(299):     at com.threed.jpct.GenericVertexController.init(GenericVertexController.java:89)
09-19 18:30:50.774: ERROR/AndroidRuntime(299):     at org.me.home.MainActivity$VertexController.<init>(MainActivity.java:372)
09-19 18:30:50.774: ERROR/AndroidRuntime(299):     at org.me.home.MainActivity.onKeyDown(MainActivity.java:175)
09-19 18:30:50.774: ERROR/AndroidRuntime(299):     at android.view.KeyEvent.dispatch(KeyEvent.java:1037)
09-19 18:30:50.774: ERROR/AndroidRuntime(299):     at android.app.Activity.dispatchKeyEvent(Activity.java:2068)
09-19 18:30:50.774: ERROR/AndroidRuntime(299):     at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchKeyEvent(PhoneWindow.java:1643)
09-19 18:30:50.774: ERROR/AndroidRuntime(299):     at android.view.ViewRoot.deliverKeyEventToViewHierarchy(ViewRoot.java:2471)
09-19 18:30:50.774: ERROR/AndroidRuntime(299):     at android.view.ViewRoot.handleFinishedEvent(ViewRoot.java:2441)
09-19 18:30:50.774: ERROR/AndroidRuntime(299):     at android.view.ViewRoot.handleMessage(ViewRoot.java:1735)
09-19 18:30:50.774: ERROR/AndroidRuntime(299):     at android.os.Handler.dispatchMessage(Handler.java:99)
09-19 18:30:50.774: ERROR/AndroidRuntime(299):     at android.os.Looper.loop(Looper.java:123)
09-19 18:30:50.774: ERROR/AndroidRuntime(299):     at android.app.ActivityThread.main(ActivityThread.java:4627)
09-19 18:30:50.774: ERROR/AndroidRuntime(299):     at java.lang.reflect.Method.invokeNative(Native Method)
09-19 18:30:50.774: ERROR/AndroidRuntime(299):     at java.lang.reflect.Method.invoke(Method.java:521)
09-19 18:30:50.774: ERROR/AndroidRuntime(299):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
09-19 18:30:50.774: ERROR/AndroidRuntime(299):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
09-19 18:30:50.774: ERROR/AndroidRuntime(299):     at dalvik.system.NativeStart.main(Native Method)


Let me try that

my idea is when I keep click on a button, I shoud get my cube enlarged on x-axis that will have a wall kind of look or by some  other means.Eearlier I used scale factor.But the problem is my cube has been scaled to a bigger one. I do not want that.For example, It is like in 3d modelling tool where I click x-axis, it will increase its size on x-axis.Something similar to that.

one more clarification,I have a box.As per the above pic, if I place one more box next to previous one, then what I need to do is share the vertices of the previous box.Then I think, the placing issues can be resolved.This is what @EgonOlsen has suggested.But using API , I do not know how to do it.

I have to try it out that way