How to get the depth of translucent objects through PickDepth?

[SAYEOR]

The depth I got came from viewer.scene._view.pickDepths[0]._depthTexture, as you can see from the image below, translucent object do not have depth values. Is there a way to get the depth of a translucent object?

1. An opaque box

box: {
    dimensions : new Cesium.Cartesian3(80000.0, 80000.0, 20000.0),
    material : Cesium.Color.RED
}

2. A translucent box

box: {
    dimensions : new Cesium.Cartesian3(80000.0, 80000.0, 20000.0),
    material : Cesium.Color.RED.withAlpha(0.5)
}