VR SLICE

# VR Slicer (Forge 1.20.1)

Real sword cuts in VR. Swing a sword or axe hard through any mob and it's cut in two exactly where your blade went, like the Roblox game *Smooth Slicing*.
The pieces fall as ragdolls with realistic cut faces, and they stay on the ground. You can keep slicing them.
Swing your arm hard while holding a throwable and you throw it.

## Install
Put `vrslicer-1.20.1-forge-1.0.0.jar` in your `mods` folder (Forge 1.20.1, 47.x), together with **Vivecraft for Forge 1.20.1, version 1.3 or newer**.
For multiplayer, the server needs the mod too (cuts and throws are checked and done by the server). Vivecraft on the server is optional.

## Slicing
* Hold a **sword or axe** (any modded sword or axe works too) and **swing it hard** through a mob.
  The cut follows the plane your blade swept: a flat swing takes the head off, a downward chop splits it down the middle, a diagonal swing cuts it diagonally.
* The mob dies and turns into **ragdoll pieces**. Parts that weren't cut apart stay joined at the shoulders, hips and neck and flop realistically.
  Cut-off heads, arms and legs roll away on their own. Everything falls, tumbles, slides to a stop and **stays on the ground**.
* **Cut faces look like the inside of the mob:** red meat with a bone in the middle for animals and people, rotten flesh for zombies, bone for skeletons,
  green for creepers, slime for slimes, glowing magma for magma cubes and blazes, iron for golems, purple for endermen, and so on.
  Fresh cuts spray and drip blood (or the right stuff for that mob) for a few seconds. Pieces thud when they land.
* **Slice the pieces again.** Swing through a body part on the ground to cut it further, as many times as you like.
* A gentle swing is just a normal hit. How hard is "hard" is set by `sliceSpeed`. Mobs with lots of health (iron golems, ravagers) need up to 50% harder swings.
* Works on **every mob**, vanilla or modded: the mod captures what the mob looks like at that moment, including armour and held items.
  Mobs built from normal Minecraft model parts get a jointed ragdoll; mobs with custom renderers (e.g. GeckoLib) are cut into two solid pieces.
* Bosses (Ender Dragon, Wither) and players can't be sliced unless the server allows it (`sliceBosses`, `slicePlayers`).
* Loot and XP drop as normal.

## Gore
* Fresh cuts **spurt blood in pulses**, like a heartbeat, for about 7 seconds, weakening as they bleed out.
* **Blood pools** spread on the ground under bleeding pieces (orange for blazes, green for creepers and slimes...).
* Cuts sound wet and meaty, with a bone crack on mobs that have bones, and the controller kicks harder.
* Blood flies in **real drops** that arc through the air and leave **splatters on floors, walls and ceilings**. Every hit bleeds, not just cuts.
* Skin around a cut is **stained with blood**, strongest right at the edge.
* Cuts tear off **chunks of meat and bone splinters** that tumble and land.
* A cut through the torso **spills the insides**: a dangling chain of intestines, a heart, two lungs, a liver and broken ribs
  (grey-green rotten guts for zombies, green goo for spiders and other bugs).
* Bodies sink away and blood pools fade out after **1 minute** (`corpseSeconds`; 0 = keep forever).

## Limbs, undead and toughness
* **Cut off legs or arms and the mob lives:** no legs = it drags itself along slowly, one leg = it limps, no arm = it can't hit you or shoot.
  It's cut down to its torso or head on the ground, and the limbs fall as ragdoll pieces.
* Living mobs die when the cut goes through the **torso or head**, or takes the **head off**.
* **Undead** (zombies, skeletons...) keep going as long as their **head is in one piece**: a zombie with its head cut off becomes a head bouncing after you.
  Cut the head itself in half to finish it.
* **Body toughness:** the more health a mob (or player) has, the harder you have to swing to cut it, up to 1.8× as hard.
* **Every death is a ragdoll**, even without a cut (`ragdollAllDeaths`).

## Settings menu
Mods → VR Slicer → **Config**: gore level (Off / Low / Normal / High / Extreme), bones in cuts, how long bodies and blood stay, and how many bodies are kept.

## Knockouts, bruises and sword zombies
* A knocked-out mob **falls over as a ragdoll but doesn't die**; it gets back up a few seconds later. Kill it while it's out and the ragdoll stays as its body.
* The body part you punch turns **purple** for 30 seconds.
* **You** get bruised when mobs hit you, and a heavy hit can **knock you out** for a couple of seconds (can't move, can't see).
* Zombies are much tougher, and some carry **swords**. They raise the sword before striking: **step back or round them to dodge**, or **hit them to parry**.
  If the strike lands it can **cut your arm**: you drop what you're holding and that arm is weak for 15 seconds.

## Hands
* **Throws** get much stronger the harder you swing.
* In VR, items aren't picked up by walking over them: **put your hand on the item and press attack** to grab it.

## Fists and tough mobs
* **Punch with an empty hand** to bruise a mob: it slows down and gets a purple spot where you hit. **Punch hard** (`knockoutSpeed`) to knock it out for a few seconds (stars over its head).
* Hold an **arrow** and stab with it for a quick hit. **Shot arrows** go straight through mobs like a spear and do 50% more damage.
* **Tough mobs** (iron golems, ravagers and anything with 50+ health, `toughMobHealth`) can't be cut or knocked out until they're down to **25% health**; until then a cut is just a heavy hit.

## Arrows
* An arrow flying at you while you hold a sword or axe goes into **slow motion**, and nearby mobs slow down too.
* **Hit it with your blade** to knock it back where you're looking. Works on any projectile (arrows, fireballs, tridents...).

## Smarter mobs
Hostile mobs are 25% faster, hit 30% harder, have 25% more health, hunt you from further away (even without seeing you),
**jump gaps and walls up to two blocks** to reach you, and **pounce** when close. All adjustable (`mobSpeed`, `mobDamage`, `mobHealth`, `smarterMobs`).

## Throwing
Hold a **snowball, egg, ender pearl, splash or lingering potion, bottle o' enchanting or trident** and **swing your arm hard** as if throwing a ball.
It leaves your hand at the top of your swing, from where your hand is, in the direction your hand was moving. Faster swings throw further.
Running or flying adds your own speed to the throw. Item cooldowns (ender pearls) and item use-up work as normal.
Modded throwables can be added with the item tag `vrslicer:throwables` or the server config `extraThrowables`.

## Without VR
* Killing a mob with a **fully charged** sword or axe hit slices it along a random swing (server setting `desktopSlicing`).
* Left-click a body piece on the ground with a sword or axe to cut it again.

## Config
Client, `config/vrslicer-client.toml`:
`vrSlicing`, `sliceSpeed` (m/s, default 4.5), `toughMobsNeedHarderSwings`, `resliceCorpses`, `vrThrowing`, `throwSpeed` (m/s, default 3.5), `throwPower`,
`maxCorpses` (default 40), `corpseSeconds` (0 = pieces stay forever), `blood`, `bloodAmount`, `bonesInCuts`, `haptics`,
`bloodTypes` (e.g. `"minecraft:pig=rotten"`; types: flesh, rotten, bone, plant, slime, magma, iron, snow, fire, ender, ghost, bug).

Server, `config/vrslicer-common.toml`:
`enableSlicing`, `minSliceSpeed`, `slicePlayers`, `sliceBosses`, `desktopSlicing`, `extraSlicingItems`, `swingThrowing`, `maxThrowSpeed`, `extraThrowables`.

## Notes
* Body pieces are drawn by each player's own game, so in multiplayer everyone sees the mob get cut the same way, but pieces may land slightly differently,
  and re-slicing pieces on the ground is only seen by you.
* Pieces don't collide with each other, only with blocks.

## How it works
1. Your controller's blade (hand to sword tip) is tracked every tick, relative to your body so walking doesn't count as swinging.
   When the tip moves faster than `sliceSpeed` through a mob, the cut plane is the plane containing the blade and its direction of motion.
2. The server checks the hit and kills the mob, then tells every nearby player to slice it.
3. Each game re-renders the mob into a recording buffer instead of the screen, so it gets the mob's exact current model as triangles,
   split into body parts with their pivot points (a small mixin on `ModelPart`).
4. Triangles crossing the plane are split. Each cube of the model is convex, so the hole is filled with the convex hull of where its faces cross the plane,
   textured with a generated flesh texture and a bone in the middle.
5. Each piece is a rigid box of 8 Verlet particles; joints are ball joints at the model's pivots; corners collide with block shapes, with friction.
   Pieces at rest go to sleep and wake if the ground under them disappears.

## Building
Requires JDK 17: `gradlew build`. The jar is written to `build/libs/`.
`gradlew runClient -PselfTest` runs an automatic test that slices a row of mobs and saves screenshots to `run/screenshots`.