Common Node and Component Interfaces

    Please review the Node and the API documentation.

    Suppose you are inside a running component script, to access a node inside the current script use .

    A node is activated by default. It’s activation state can be changed in code by setting the node’s active property. Example:

    Setting the active property and switching the active and closed states of the node in the editor have the same effect. When a node is down, all its components will be disabled. At the same time, all its child nodes and components on the child nodes will also be disabled. It should be noted that when child nodes are disabled, their active properties are not changed, so they will return to their original state when the parent node is reactivated.

    In other words, active actually represents the active state of the node itself, and whether this node current can be activated depends on its parent node. And if it is not in the current scene, it cannot be activated. We can use the read-only property activeInHierarchy on the node to determine whether it is currently activated. Example:

    1. this.node.active = true;

    If the node is in the can be activated state, modifying active to true will immediately trigger the following activation operations:

    • All components on this node and all child nodes will be enabled, and the update method in them will be executed every frame afterwards

    • If there are onEnable methods on these components, these methods will be executed

      1. this.node.active = false;
    • Hide the node and all child nodes under the node in the scene
    • All components on this node and all child nodes will be disabled, that is, the code in update in these components will no longer be executed
    • If there are methods on these components, these methods will be executed

    Change the Parent Node of a Node

    Suppose the parent node is parentNode and the child node is this.node.

    This is valid:

    This is also valid:

    1. // method 2
    2. this.node.removeFromParent();
    3. parentNode.addChild(this.node);

    These two methods are equivalent.

    this.node.children will return an array of all child nodes of the node.

    this.node.children.length will return the number of children of the node.

    Changing Node Location

    There are two ways:

    1. Use the setPosition method:

      1.  this.node.setPosition(100, 50, 100);
      2.  // Or
      3.  this.node.setPosition(new Vec3(100,50,100));

    2. Setting the variable:

    The above two usages are equivalent.

    Example:

    1. this.node.setRotation(quaternion);

    Or set local rotation by Euler angle:

    1. this.node.setRotationFromEuler(90,90,90);

    Changing Node Scale

    Example:

    • this.node: The node instance to which this component belongs.
    • this.enabled: Whether to execute the update method of the component every frame, and also to control whether the renderable component is displayed.
    • update(deltaTime: number): As a member method of the component, when the component’s enabled property is true, the code in it will be executed every frame.
    • start(): It will be executed before the first update of the component, usually used for logic that needs to be executed after the onLoad of all components is initialized.