How to Make Skybox Transparent in Filament?

[p147123456]

I'm trying to make the Skybox transparent in Filament, but so far none of the methods I've tried have worked. Here's what I've attempted:

Setting the 's clear options to transparent:Renderer

private void makeTransparentBackground() {
    this.setZOrderOnTop(true);
    this.getHolder().setFormat(PixelFormat.TRANSLUCENT);
    this.setBackgroundColor(Color.TRANSPARENT);
    modelViewer.getView().setBlendMode(com.google.android.filament.View.BlendMode.TRANSLUCENT);
   modelViewer.getScene().setSkybox(null);
    Renderer.ClearOptions options = renderer.getClearOptions();
    options.clear = true;
    options.clearColor[0] = 0.0f; // Red
    options.clearColor[1] = 0.0f; // Green
    options.clearColor[2] = 0.0f; // Blue
    options.clearColor[3] = 0.0f; // Alpha
    renderer.setClearOptions(options);
}

modelViewer.getScene().setSkybox(
    new Skybox.Builder().color(0f, 0.0f, 0.0f, 0.0f).build(modelViewer.getEngine())
);

Neither approach has worked. The background remains black. I’ve also ensured that:

The is set to .SurfaceViewPixelFormat.TRANSLUCENT
The background color is set to .SurfaceViewColor.TRANSPARENT
The alpha channel is .Renderer.ClearOptions.clearColor0.0f
What is the correct way to make the Skybox transparent in Filament?

[romainguy]

You can check the example provided: https://github.com/google/filament/tree/main/android/samples/sample-transparent-view