A real-world object in a scene for which ARKit tracks changes to position and orientation.
ARKit跟踪位置和方向变化的场景中的真实世界对象。
Overview
This protocol is adopted by ARKit classes, such as the ARFaceAnchor class, that represent moving objects in a scene.
ARKit automatically manages representations of such objects in an active AR session, ensuring that changes in the real-world object's position and orientation (the transform property for anchors) are reflected in corresponding ARKit objects. The isTracked property indicates whether the current transform is valid with respect to movement of the real-world object.
概述
该协议被ARKit类所采用，例如ARFaceAnchor类，它们表示场景中的移动对象。
ARKit自动管理活动AR Session中的这些对象的表示，确保现实世界对象的位置和方向（锚的转换属性）的更改反映在相应的ARKit对象中。 isTracked属性指示当前变换对于真实世界对象的移动是否有效。
Monitoring Tracking State
isTracked
A Boolean value that indicates whether the object’s transform is valid.
一个布尔值，指示对象的变换是否有效。
Required.
Discussion
If this value is YES, the object’s transform currently matches the position and orientation of the real-world object it represents.
If this value is NO, the object is not guaranteed to match the movement of its corresponding real-world feature, even if it remains in the visible scene.
讨论
如果此值为YES，则该对象的变换当前与它所表示的现实世界对象的位置和方向相匹配。
如果此值为“否”，则不保证该对象与其对应的真实世界特征的移动相匹配，即使该对象保留在可见场景中。
Inherits From NSObject
Adopted By ARFaceAnchor
