Author Topic: z-sorting problem  (Read 642 times)

Offline sunghoney

  • byte
  • *
  • Posts: 1
    • View Profile
z-sorting problem
« on: January 23, 2013, 06:52:38 am »
obj files created on a Blender.






checked in android ...








The problem occurs when we rotate.



Code: [Select]
public class TestActivity extends Activity {

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

   private GLSurfaceView mGLView;
   private MyRenderer renderer = null;
   private FrameBuffer fb = null;
   private World world = null;
   private RGBColor back = new RGBColor(255, 255, 255);

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

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

   private Object3D object = null;
   private int fps = 0;

   private Light sun = null;

   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);
      }
   }

   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);
   }

   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(100, 100, 100);

            sun = new Light(world);
            sun.setIntensity(255, 255, 255);
           
            try {
               TextureManager.getInstance().addTexture("test.png", new Texture(getAssets().open("maps/test.png"), true));
            } catch ( IOException e ) {
            }

            object = loadModel("untitled", 3);
            //object.rotateX((float) (-180 * Math.PI / 180));
            object.setCenter(new SimpleVector());
            object.setTransparency(15); //Necessary for transparent textures
            object.build();
            world.addObject(object);

            SimpleVector sv = new SimpleVector();
            sv.set(object.getTransformedCenter());

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

            sv.set(object.getTransformedCenter());
            sv.z -= 10;
            sun.setPosition(sv);
            MemoryHelper.compact();

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

      private Object3D loadModel(String filename, float scale) {
         AssetManager assetManager = getResources().getAssets();
         Object3D[] model = null;
         try {
            model = Loader.loadOBJ(assetManager.open(filename + ".obj"), assetManager.open(filename + ".mtl"), scale);
         } catch ( IOException e ) {
         }
         return Object3D.mergeAll(model);
      }

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

      public void onDrawFrame(GL10 gl) {
         if( touchTurn != 0 ) {
            object.rotateY(touchTurn);
            //world.getCamera().rotateY(touchTurn);
            touchTurn = 0;
         }

         if( touchTurnUp != 0 ) {
            object.rotateX(touchTurnUp);
            //world.getCamera().rotateX(touchTurnUp);
            touchTurnUp = 0;
         }

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

         if( System.currentTimeMillis() - time >= 1000 ) {
            Log.i("ROOEX", "fps : " + fps);
            fps = 0;
            time = System.currentTimeMillis();
         }
         fps++;
      }
   }
}



Can anyone advise on this issue?
« Last Edit: January 23, 2013, 06:56:55 am by sunghoney »

Offline EgonOlsen

  • Administrator
  • quad
  • *****
  • Posts: 11777
    • View Profile
    • http://www.jpct.net
Re: z-sorting problem
« Reply #1 on: January 23, 2013, 08:06:38 am »
Transparent object will be sorted per object. In this case, all objects are merged into one and so they can't be sorted correctly in all cases. You have two options: Don't merge them into one or don't use transparency on them.