Shape Borders is a Forge 1.20.1 mod that replaces Minecraft's square world border with a custom shape
Description
Shape Borders is a Forge 1.20.1 mod that replaces Minecraft's square world border with a custom shape of your choice — circle, oval, rectangle, star, or creeper head — while keeping the look and feel of the vanilla forcefield.
It's server-authoritative (the chosen shape persists per-dimension and syncs to all clients on join), uses Mixins to hook directly into WorldBorder and LevelRenderer so it stays compatible with heavily modded servers, and ships a single op command /shapesborder