Touch detection - 3D object in 3D space?

cocos2d-x
1

Hi! The cocos2d-x tests have a nice demo showing how to detect touch events on 3D objects in a 2D space (Sprite3DHitTest in tests/cpp-tests/Classes/Sprite3DTest/Sprite3DTest.cpp).

I’m having trouble finding an example that shows how to adapt this to detecting which 3D object is touched in a 3D space. I’d appreciate a point in the right direction, or better yet, some demo code.

Thanks so much!

Erik

2

I had just found the way how

    ...

    auto listener1 = EventListenerTouchOneByOne::create();
    listener1->setSwallowTouches(true);
    
    listener1->onTouchBegan = CC_CALLBACK_2(HelloWorld::onTouchBegan,this);

    _eventDispatcher->addEventListenerWithSceneGraphPriority(listener1, _player);

    ...


bool HelloWorld::onTouchBegan(cocos2d::Touch* touch, cocos2d::Event* event)
{
    // get the Sprite3D
    auto target = static_cast<Sprite3D*>(event->getCurrentTarget());
//
    // get z position of Sprite3D
    float z = target->getPositionZ();
//
    // convert rect in 3D screen (camera) TO rect in 2D screen GL
//    
    //// get boudingbox => rect in 3D screen (camera)
    Rect rect = target->getBoundingBox();
//    
    //// using camera projectGL to get LB point, and RT point in 2D screen from "3D Rect"
    Vec2 LeftBottom = _camera->projectGL(Vec3(rect.origin.x, rect.origin.y, z));
    Vec2 RightTop = _camera->projectGL(Vec3(rect.origin.x + rect.size.width, rect.origin.y + rect.size.height, z));
//    
    //// define rect2 from new points (LB and RT)
    Rect rect2 = Rect(LeftBottom.x, LeftBottom.y, RightTop.x - LeftBottom.x, RightTop.y - LeftBottom.y);
//
    
    //// location of touch in 2D screen
    Point p = touch->getLocation();
//
    //// detect p in rect2...
    if (rect2.containsPoint( p ))
    {
        log("sprite3d began... x = %f, y = %f", touch->getLocation().x, touch->getLocation().y);
        target->setOpacity(100);
        return true;
    }
    return false;

}
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