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I'm implementing OutlinePass on my project, with EffectComposer, FXAAShader, CopyShader and ShaderPass included. I've followed the steps in the example, yet these 2 errors appeared and the whole scene was pitch black. I have no idea how to fix them since they all pointed to the included OutlinePass library. Any one has any idea of how to fix these? Thanks a lot!

Errors:

> Uncaught TypeError: Cannot read property 'prototype' of undefined
    at OutlinePass.js:131
> Uncaught TypeError: this.getPrepareMaskMaterial is not a function
    at new THREE.OutlinePass (OutlinePass.js:45)
    at init (script.js:89)
    at script.js:219

Here is the code:

    var OUTLINE;
    var COMPOSER;
    var FXAA;

    function init() {
        scene.add(controls.getObject());

        COMPOSER = new THREE.EffectComposer(renderer);

        var renderPass = new THREE.RenderPass(scene, camera);
        COMPOSER.addPass(renderPass);

        FXAA = new THREE.ShaderPass(THREE.FXAAShader);
        FXAA.uniforms['resolution'].value.set(1 / window.innerWidth, 1 / window.innerHeight);
        FXAA.renderToScreen = true;
        COMPOSER.addPass(FXAA);

        OUTLINE = new THREE.OutlinePass(new THREE.Vector2(window.innerWidth, window.innerHeight), scene, camera);
        OUTLINE.edgeStrength = 6;
        OUTLINE.edgeGlow = 1;
        OUTLINE.edgeThickness = 4;
        OUTLINE.pulsePeriod = 2;
        OUTLINE.visibleEdgeColor = 0xffff00;
        OUTLINE.hiddenEdgeColor = 0xffffff;
        COMPOSER.addPass(OUTLINE);
    }

    function animate() {
        requestAnimationFrame(animate);
        COMPOSER.render();
    }