Tommy Leung from Ourcade presents a new tutorial: "A reveal effect is where an image on top is erased to reveal another image below it. This can be used for a simple scratch-off mini-game or a more complicated spotlight or flashlight effect.
There are multiple ways to achieve this effect in Phaser 3 and in this article, we will look at using a RenderTexture as an alpha mask. If your reveal effect is fairly simple then you may be able to use a simpler method discussed here.
The basic premise is that we will put two images – a cover image and a reveal image – on top of each other and then mask them both with a RenderTexture..."