Place Anywhere Core

Blocks placed with this library store double-precision coordinates and a quaternion rotation, so they can be placed at sub-block offsets and at any angle, not only the four steps vanilla allows. The positions and rotations survive saving and reloading, because they are kept in a parallel data layer laid over the vanilla chunks.

Collision is handled with oriented bounding boxes tested by the separating axis theorem, and movement is clipped with a per-axis bisection of ten iterations. Entities can climb slopes and are pushed out of small overlaps. The library also covers rendering with correct lighting, raycasting, mining, redstone signals, neighbor updates, container screens and NBT serialization, and it injects 22 Minecraft internals through mixins to make the free blocks interactive.

Only the server and players need it: the environment is client and server. The library is open source under the GNU Lesser General Public License v3.0 only and is published for Fabric, Forge and NeoForge, across 6 release versions in the 1.18.2 – 1.21.1 range. The author notes the project is still in early development with many bugs.