Its working now,
It was the frame buffer clearing problem, in vuforia native code it was disabled by mistake.
Thanks a lot for your help.

No, I havent used fb.clear. I have used fb.dispose in onsurfacechanged() though.
Where should I use fb.clear, in Renderer ondrawframe() or after , in my main activity where I am adding obj to world.?

this is the render loop in renderer,

/** Called to draw the current frame. */
    public void onDrawFrame(GL10 gl)
    {
       if (!mIsActive)
         return;
      
      
      if (mActivity.touchTurnUp != 0 && mActivity.isadded != false) {
         mActivity.new_thing.rotateZ(mActivity.touchTurnUp);
         //cube.rotateX(0.1f);
         mActivity.touchTurnUp = 0;
      }

      // Update render view (projection matrix and viewport) if needed:
      mActivity.updateRenderView();
      
      screenX1 = mActivity.screenX;
      screenY1 = mActivity.screenX;
      //mActivity.new_thing.animate(index, seq)
      
      
      updateCamera();
      renderFrame();
      
      
      world.renderScene(fb);
      world.draw(fb);
      //thing.animate(1, 1);
      fb.display();
    }


and this is where I add new texture and model to world in my main activity, in background thread

try {
            modelstrm = new FileInputStream(new File(imagePath));
            mtlstrm = new FileInputStream(new File(MaterialPath));
            texstrm = new FileInputStream(new File(TexturePath));

            System.out.println("Start loading 3D model");
            // fb = new FrameBuffer(mScreenWidth, mScreenHeight);

            try {

               System.out.println("Start loading Texture");

               // old_texture = new
               // Texture(BitmapHelper.rescale(BitmapHelper.convert(getResources().getDrawable(R.drawable.ic_launcher)),
               // 64, 64));
               TextureManager tm = TextureManager.getInstance();
               if (!tm.containsTexture("new_texture")) {
                  new_texture = new Texture(BitmapHelper.rescale(
                        BitmapHelper.loadImage(texstrm), 512, 512));
                  // tm.unloadTexture(fb, new_texture);
                  // tm.r
                  // tm.replaceTexture("new_texture", old_texture);
                  new_texture.compress();
                  tm.addTexture("new_texture", new_texture);
               } else {
                  old_texture = new Texture(BitmapHelper.rescale(
                        BitmapHelper.loadImage(texstrm), 512, 512));
                  // tm.addTexture("new_texture", new_texture);
                  old_texture.compress();
                  tm.replaceTexture("new_texture", old_texture);
               }
               // tm.unloadTexture(mRenderer.fb, old_texture);
               System.out.println("End loading Texture");

            } catch (Exception e) {
               // TODO Auto-generated catch block
               e.printStackTrace();
            }

            if (isadded) {
               new_thing.clearObject();
               new_thing = Object3D.mergeAll(Loader.loadOBJ(modelstrm,
                     mtlstrm, 1.0f));
               new_thing.setTexture("new_texture"); // somtheing is wrong
                                             // here
               new_thing.scale(2.0f);
               // isadded = true;
               isadded = false;
            }

            new_thing = Object3D.mergeAll(Loader.loadOBJ(modelstrm,
                  mtlstrm, 1.0f));
            new_thing.setTexture("new_texture"); // somtheing is wrong here
            // new_thing.scale(2.0f);
            isadded = true;

            // new_thing.translate(0, 0, 50);
            new_thing.rotateX(90);
            System.out.println("End loading 3D model");

         } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
         }

         // dismissDialog(progress_bar_type);

         if (inputStream != null)
            Log.d("TAG", "It worked!");
         mRenderer.world.addObject(new_thing);
         pDialog.dismiss();

      }




Its not the cleanest of codes so please bear with

sorry

[attachment deleted by admin]