I'm making a 2d platformer, and I would like the level to look like you are standing on a small planet. I'm thinking about using a shader to accomplish this. I had never used them before so, with help from this post, I managed to create something similar to what I was imagining:
This is the code I used. The shader is applied in a ColorRect node that is parented by a CanvasLayer node, in order to apply the effect to the entire viewport.
This is the result. It works as intended, but it's not exactly what I wanted. The effect is too extreme. I want to have at least some control over how big the "planet" is. I don't really want everything just come crashing down when it hits the border. This is especially noticeable when we resize the screen:
The ColorRect resizes along with it, making the effect even more extreme.
So I want to know either how I can improve this shader, or if there already exist resources that do something similar so I can implement them in my game. If neither, I can just ditch this idea altogether, no problem. I don't know if I'm asking for too much...