Block Reality 0.2a

Structural Preview for Minecraft 1.20.1 + Forge 47.x: real finite
element analysis on the blocks you place, from an engine running outside
the game process.

What this preview does

• extracts placed blocks into 6-DOF beam members and MITC4 shell facets
  (floors and shear walls), one structure per connected component
• solves them with self weight plus point test loads (/br load, in kN,
  any direction), off the tick thread, over a zero-copy shared-memory
  transport
• reports per-member and per-plate demand/capacity with the governing
  fibre named, stress contours on the block faces, a section readout
  with the neutral axis, and a linear buckling factor — a slender column
  that "looks safe" on stress says so
• nine structural blocks: three steel sections, plain concrete, timber,
  a brick pier, two slab thicknesses, 20 mm steel plate — and they mix:
  a timber beam on brick piers is one structure, joined where the blocks
  touch, not three that ignore each other
• every number is gated: 251 acceptance checks against closed forms and
  invariants per build, record in evidence/VERIFICATION.md

Commands that change something — /br load, /br unload, /br scan,
/br resolve and /br reset — need operator level 2, which a single-player
creative world has by default. The Stress Glasses need no permission: they
apply one configured downward test load. Reading commands (/br status,
members, section, loads) are open to everyone.

What it deliberately does not do yet

• no fracture, collapse or falling-block consequences — analysis reports;
  nothing breaks or falls
• no construction sequencing, no reinforced-concrete composite sections
  (the concrete beam is honestly plain), no load combinations or wind
• linear elastic only; the buckling factor is the linear onset, an upper
  bound on the real critical load

Install: download blockreality-0.2a.zip, extract, then
run install.bat on Windows or ./install.sh on Linux. The installer
finds your Minecraft instance and copies the mod and the engine in.
macOS: the mod installs and plays, but no macOS engine binary ships yet —
analysis stays off unless you build br-sidecar from source.

Contents: the mod jar, the analysis engine for Windows and Linux x86-64,
the installers, and instructions in START-HERE.txt and 讀我-中文.txt.
SHA256SUMS.txt lists the hash of every file.