Formula for procedural Sphere from the cube?

[anonymous_user_287879af]

@StyvakLight

It is possible to send me all the code about the sphere or to upload your project ? To have a better view about what can be wrong

Thanks for the help, but I have already managed to fix it
I realized that by your formula, my only plane was simply divided into 4 parts.
Having played a little with the values I got what I wanted