Right now I'm using a super basic movement script to move an entity around and I'm limiting the entities position with clamp()'s.

This gives the effect of the entity being confined to a cube. It works, but, I need the boundary to be a sphere, not a cube. Kind of like moving an entity that is chained to a post, it shouldn't be able to move farther away than X in any direction.

I'm not quite sure how to do that! I could use some help