object is null while object picking

[hisong]

Hi, I am again.
I am doing a test about picking with JPCT-AE , so I consulted the threads(http://www.jpct.net/forum2/index.php?topic=1601.0 and http://www.jpct.net/wiki/index.php/Picking) about picking.

I did like the thread discussed, but I always get the null result! I don't know why.

This is the code sample.

I get two objects of Object3D from the 3ds file: cube[0] and cube[1],  I want to pick the cube[1] in the world.
so I set the cube[1] to be picked:

Code Select Expand


try {
cube = Loader.load3DS(
new FileInputStream("/sdcard/jpct/sphere.3ds"), 1);
Loader.clearCache();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

cube[0].setTexture("texture");
cube[0].strip();
cube[0].build();
world.addObject(cube[0]);

cube[1].setTexture("mark");
cube[1].strip();
cube[1].build();
world.addObject(cube[1]);

cube[1].setCollisionMode(Object3D.COLLISION_CHECK_OTHERS);



and then I was doing picking like this as the thread http://www.jpct.net/wiki/index.php/Picking  did.

Code Select Expand


SimpleVector dir=Interact2D.reproject2D3DWS(world.getCamera(), fb, (int)AppConfig.screenX, (int)AppConfig.screenY ).normalize();;
Object[] res = world.calcMinDistanceAndObject3D(world.getCamera().getPosition(), dir, 10000 /*or whatever*/);
judgePicking(res[1]);


Code Select Expand


public void judgePicking(Object object)
{
if(object.equal(cube[1]))
{
Log.i("Path", "Picking");
}
else {
Log.i("Path", "NULL");
}
}


I always get "null" from the function of "judgePicking()". I don't know what goes wrong.
anyone could help me?  Thanks very much.

[Thomas.]

you compare Object and Object3D...
...
judgePicking((Object3D)res[1]);
...
public void judgePicking(Object3D object){...}

[hisong]

you compare Object and Object3D...
...
judgePicking((Object3D)res[1]);
...
public void judgePicking(Object3D object){...}

Thank you for replying so quickly.
I did what you said above. It didn't work.
What's more I think it does needn't to do this because the Object3D is the subclass of Object.
the parameter Object of judgePicking(Object3D object) will do explicit casts.

[Thomas.]

and what you have in AppConfig.screenX?

[hisong]

and what you have in AppConfig.screenX?

The AppConfig class stores the values of the screen coordinate I got from the onTouchEvent(MotionEvent e).

The screenX and screenY are the static variables of AppConfig Class.

[hisong]

Thomas.  I think I found what causes the question：  It may be I don't subtract the offset of the title when I was using the screen coordinate.

It helps me a lot with the thread:http://www.jpct.net/forum2/index.php/topic,2191.msg16277.html#msg16277
I suggest that the doc would be better if the doc could be more detailed.

Thanks all who viewed this post.

Hisong

[stownshend]

I may have had the same problem, and ended up removing the status and title bars from my program (which I would have done anyway for aesthetics):

Code Select Expand


protected void onCreate(Bundle savedInstanceState)
{
// Disable the title bar or it will throw off our picking coordinates.
requestWindowFeature(Window.FEATURE_NO_TITLE);

// Disable the status bar or it will throw off our picking coordinates.
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);

... (etc)