Three.js-访问场景中的子对象 [英] Three.js - accessing a child object in a scene

问题描述

我正在尝试访问场景中的子对象sole.我可以使用obj在加载器函数内部访问var sole，但是我需要从加载器函数外部访问它.

I'm trying to access the child object sole in a scene. I am able to access the var sole inside the loader function using obj, but I need to access it from outside the loader function.

这是工作代码， 这是json模型文件.

我可以从加载器内部访问它，如下所示:

I can access it from inside the loader, like this:

var loader = new THREE.ObjectLoader();  
loader.load("models/shoe4.json", function (obj) {
    scene.add (obj);
    scene.rotation.y = Math.PI/1;
    scene.position.y = -5;
    scene.position.z = -24;

    var sole = obj.getObjectByName( "sole", true );
    sole.position.y = -5;

});

但是我需要做这样的事情:

But I need to do something like this:

var loader = new THREE.ObjectLoader();  
loader.load("models/shoe4.json", function (obj) {
    scene.add (obj);
    scene.rotation.y = Math.PI/1;
    scene.position.y = -5;
    scene.position.z = -24;     
});

var sole = obj.getObjectByName( "sole", true );
sole.position.y = -5;

基本上，我需要把它当作自己的函数供以后使用.

Basically I need to put it it's own function for later use.

我也尝试过

var sole = scene.getObjectByName( "sole", true );
sole.position.y = -5;

哪个给了我错误:

未捕获的TypeError:无法读取未定义的属性'getObjectByName'

如何从任何地方访问对象sole?仅仅声明var obj,不起作用.

How do I access the object sole from anywhere? Simply declaring var obj, is not working.

推荐答案

首先，您要在lambda函数的作用域之外声明sole，如下所示:

First you declare sole outside the scope of the lambda function, like this:

var sole = null;
var loader = new THREE.ObjectLoader();  
loader.load("models/shoe4.json", function (obj) {
    scene.add (obj);
    scene.rotation.y = Math.PI/1;
    scene.position.y = -5;
    scene.position.z = -24;

    sole = obj.getObjectByName( "sole", true );
    sole.position.y = -5;

});

// this will FAIL because sole is undefined when this line of code executes
sole.position.x = 5;

第二，程序必须在实际执行lambda函数之后 后才能访问sole.如果您不熟悉异步(或事件驱动)编程模型，那么应该对它进行一些阅读:

Second, the program must not access sole until after the lambda function is actually executed. If you're not familiar with the asynchronous (or event-driven) programming model, then you should do a little reading about it:

http://code.tutsplus.com/tutorials/event-based-programming-what-async-has-over-sync--net-30027

https://msdn.microsoft.com/zh-我们/library/windows/apps/Hh700330.aspx

这篇关于Three.js-访问场景中的子对象的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！