Fysik

Fysik

Structural physics for Valheim building. In vanilla Valheim, a piece only cares about how far it is from the ground. With Fysik, the shape of your build matters, in the spirit of Poly Bridge and Bridge Constructor.

A 24 m bridge from the building guide, every piece colored by the stress Fysik computes: the worst is at 42%, and it goes up without scaffolding. The parts list and building order are in the picture.

How it works

• Everything weighs, and the weight has to reach the ground through the pieces below. Fysik

calculates the forces in every piece as you build.

• Shape matters. Arches carry their load in compression and span gaps a flat beam cannot. Braces

and triangles carry load along their length instead of bending. Cantilevers bend, more the further they reach.

• Stone is masonry. Stones rest on each other and cannot pull: each needs something under its

weight, and an arch of the wedge-shaped arch stones stands once its keystone is in.

• New stone pieces: arch stones, curved tower stones for round towers and rounded corners, and

stone walls and floors half as thick. Stone walls and floors are cut to fit around arches and towers, and wooden floors and walls around towers.

• Colors show the stress: blue is relaxed, green is fine, yellow is getting close, red is at the

limit.

• Overloaded pieces crack before they fall: they turn red, shake and creak for a few seconds,

time to shore them up. Then whatever they held comes down with them.

• Not only the pieces weigh: furniture, full chests, players walking across, a loaded cart

rolling over a bridge and the snow piling up on roofs in the Deep North.

Quick start

1. Back up your world, or better, start a new one (see the warning below).
2. Install with r2modman or Thunderstore Mod Manager. On a server, the server and every player

need Fysik, with the same version.

1. Watch the ghost while building: before you place a piece, it is colored by the stress it would

have. Red would break.

1. Aim the hammer at a piece to read its stress (Bending 72%), its weight, the weight it holds

up (Holds 6.5 t) and whether it stands on the ground (Rests on the ground).

1. Press F7 for the X-ray: every piece within 40 m colored by stress (Ctrl+F7 widens it).
2. When something cracks, put a post or a brace under it, or take the load off, before it falls.
3. Build like a carpenter: posts every 2 to 4 m, a diagonal brace under anything that reaches out,

an arch or a truss to cross a wide gap.

Worked examples, every number explained and answers to common questions are in the wiki.

A castle from the building guide: round towers of Fysik's tower stones, stone walls cut to fit them, an arched gate whose stones are all cut to fit, and a wooden wall walk on knee braces behind the merlons. Worst piece 67%; the guide also has one with walls 2 m thick and a stone wall walk.

> ### ⚠ Before you install > > Fysik is on from the start. As soon as a world loads, every building made by players is checked > against the physics Fysik applies, and buildings that do not respect it will crack and fall, > including bases you built before installing it. Back up your world first. We recommend > starting a new world with Fysik, so everything you build is designed for it from the first post. > > Buildings that come with the world (stone towers, abandoned houses, villages, ruins) are not > simulated: they keep vanilla support, unless the server sets Structure.WorldBuildings = Physics > (see Server admins in the wiki). > > Updating from 0.1.x? Since 0.2.0 stone, black marble and grausten rest on each other like real > masonry instead of being glued. Stone that only held because it was glued falls: overhangs past > the stone below, slabs held only by the side of a wall, blocks over a doorway with nothing under > them, half-built arches. Back up your world before updating and look over your stone builds with > the X-ray (F7), or have the server set Structure.MasonryJoints = false to keep stone glued as before. > > The arch stones, tower stones and thin stone walls and floors are Fysik's own pieces: a world > keeps them only while Fysik is installed.

The physics

Wood and iron follow beam theory: a piece is strong squeezed or pulled along its length and much weaker bent across it, so braces, trusses and arches beat long beams. Stone follows masonry theory: blocks rest on each other, and what counts is where the force passes through the joints between them.

Status

> Early access. Material values are still being calibrated. Back up your worlds before trying > it.

Installation

Install with a mod manager (r2modman, Thunderstore Mod Manager) or manually: