Is there a way to control alpha of a highlight layer? The use case is I want to animate the opacity of the highlight layer. Would appreciate any suggestions. Thanks.
You may try to use
neutralColor parameter -HighlightLayer | Babylon.js Documentation
Here is the example with glow layer - https://playground.babylonjs.com/#1K48LV#1
With highlight layer it will be basically the same, something like
var hl = new BABYLON.HighlightLayer("hl1", scene); hl.neutralColor.a = 0;
alpha should not work with higlights but can work with glow
Here we are: - https://playground.babylonjs.com/#1KUJ0A#436