Facebook AR - Javascript

Question

我正在使用Facebook AR Studio，并大致遵循了本教程以满足我的需求：https://blog.tallan.com/2018/04/24/facebook-ar-studio-how-to-use-tap-gestures-to-change-effect-materials/。

然而，当我尝试播放我的项目时，它给了我一个错误-

JavaScript error: Exception in native code while calling afunction: Child not found: ScreenCanvas回溯

下面是我使用的代码。

//includes for base libraries
var Scene = require('Scene');
var Tap = require('TouchGestures');
var Mat = require('Materials');

// base dir
var base = 
Scene.root.child('Device').child('Camera').child('Focal 
Distance');
var sCanvas = base.child('ScreenCanvas');
var NoEffectButton  = sCanvas.child('NoEffectButton');
var StageOneButton  = sCanvas.child('StageOneButton');
var effectVisibility = false;

// facemesh

var faceMesh = 
base.child('facetracker0').child('StageOneFaceMesh');


Tap.onTap(NoEffectButton).subscribe(function(event){
                                setEffectVisibility(false);
                                });

Tap.onTap(StageOneButton).subscribe(function(event){
                                faceMesh.material = 
Mat.get('coldsore');
                                setEffectVisibility(true);
                                });

function setEffectVisibility(option){
    if(effectVisibility !== option){
    effectVisibility = option;
    faceMesh.cameraVisibility.forFrontCamera = effectVisibility;
    faceMesh.cameraVisibility.forRearCamera = effectVisibility;
    faceMesh.cameraVisibility.forUnspecifiedCamera = 
effectVisibility;
   }
}

Answer 1

这很可能意味着场景中没有名为"ScreenCanvas“的对象作为"base”的子对象。您可能只是目标错误，或者有一个拼写错误。

尝试使用Diagnostics.log(base)来确保您的目标元素是正确的。祝好运!