Simple scene creation with Godot only

It's just a matter of creating a national flag using the 2D gradient texture that Godot has. Then animate the flag with the shader from GDQuest.

Personal opinion
- If it's a big game, you shouldn't use shader movement.
-Shader movement consumes a lot of resources.
-Using things that Godot facilitates a lot will make the game lag.

I've tried converting shader code to visual shader, and I found that it has a slight lag. This is just for one object, if it's more than that it might cause something undesirable.