[]我想动态改自定义shader里的值，应该怎么写？？

我想动态改自定义shader里的值，
CustomMaterial.js应该怎么写？？我这样写set的时候报错
Uncaught TypeError: this._setValue is not a function at CustomMaterial.setAlphaTestValue (CustomMaterial.js:34) at LayaAir3D.js:94CustomMaterial.setAlphaTestValue @ CustomMaterial.js:34
(anonymous)



function CustomMaterial() {

    CustomMaterial.__super.call(this);

    this.setShaderName("CustomShader");

}

 

Laya.class(CustomMaterial, "CustomMaterial", Laya.BaseMaterial);

 

CustomMaterial.DIFFUSETEXTURE = 1;

CustomMaterial.NORMALTEXTURE = 2;

CustomMaterial.ALPHATESTVALUE = 0;

 

CustomMaterial.prototype.getDiffuseTexture = function () {

    return this._getTexture(CustomMaterial.DIFFUSETEXTURE);

}

 

CustomMaterial.prototype.setDiffuseTexture = function (value) {

    this._setTexture(CustomMaterial.DIFFUSETEXTURE,value);

}



CustomMaterial.prototype.getNormalTexture = function () {

    return this._getTexture(CustomMaterial.NORMALTEXTURE);

}

 

CustomMaterial.prototype.setNormalTexture = function (value) {

    this._setTexture(CustomMaterial.NORMALTEXTURE,value);

}



CustomMaterial.prototype.getAlphaTestValue = function () {

    return this._getValue(CustomMaterial.ALPHATESTVALUE);

}

 

CustomMaterial.prototype.setAlphaTestValue = function (value) {

    this._setValue(CustomMaterial.ALPHATESTVALUE,value);

}