Tumblebox

Manual

a StuStudios game

A materials test chamber. Pour, heat, spark and drop things, and read what happened: every cell carries a temperature in degrees, the air carries pressure, metal and salt water carry current, and the dummies are here to be measured.

Hands

Left drag: Use the selected element or tool
Right drag: Erase, or delete the body under the cursor
Middle drag: Grab and throw a body with any tool (or Alt + left)
Shift · Ctrl drag: A straight line · a filled box (or the switch beside the brush)
Middle click · Q: Pick up the element under the cursor
Wheel · [ ]: Brush size
Space · .: Pause · one tick at a time
T: Slow motion
V: Normal, heat and air views
R: Replace: paint over cells, not only into air
Ctrl Z: Undo the last stroke, spawn or scene
1 – 8: Dock categories · E picks Drag

How the box works

The world is a grid of cells, sixty ticks a second. Powders fall and pile, liquids fall and spread, gases rise and thin out, and anything denser sinks through anything lighter. Every neighbouring pair of cells trades heat each tick at the pair's conductivity, which is why metal heats through and wood chars from the outside in. A cell melts, boils, freezes or catches fire when its own number crosses the line on its card.

Air lives on a coarser grid of four-by-four blocks with pressure and flow. A blast is a pressure spike that spreads, shatters glass, sets off nitro and shoves everything loose. Current jumps from conductor to conductor up to two cells away, then the conductor rests for a moment, so a battery sends pulses down a wire. Rust does not conduct, and neither does pure water.

Bodies are points tied with springs, run twice a tick. Each tick every body stamps its filled shape into the grid: cells treat that shape as solid, and anything loose inside it is pushed out, which is the splash. The dummies pull themselves upright on invisible strings while they can, swim when they are wet, flail when they burn and go limp when knocked out. Their joints only bend the right way, and they snap.

A rope is a chain of light points tied to whatever its ends started on, or to the back wall: it only pulls, it burns through, and it snaps if yanked. A rocket clicked onto a body is strapped to it and turns with it, and its thrust and weight act on the body at that point.

Things to try

Run a wire from a battery into pure water, then salt the water.
Heat sand until it turns to glass, then pour acid into your glass.
Drop a dummy into liquid nitrogen, then drop the weight on it.
Pile thermite on a metal plate and light it with lightning.
Watch a gunpowder chain in the air view, at slow motion.
Strap a rocket to a dummy's chest and touch it with a spark.
Run a fuse into a block of C-4 and light the far end.
Hang a crate from a rope over a fire and wait.

Test log

Every change the element cards describe, and everything the bodies can do, ticked off the first time you make it happen. Only what your hand is in counts: what you place, heat, cool, spark, blow up, erase beside or move, and whatever that sets off. A scene's own machinery fills nothing: the Furnace's heater melting its own ice is the heater's doing, and the Bench's battery keeping its own lamp lit is the battery's. Every entry can be made with the dock alone. Each day it picks three of your blanks to try, and as it fills, the Box menu opens new rigs.

Work orders

Each day the Box menu holds a work order, the same rig for every player: a goal, a ration of materials and a clock that runs only while the box does. It starts paused, so lay your ration out first; slow motion costs nothing, undo puts the box back but not the clock, and Clear starts the order over. Pass it and the result line, with the date, the order, your time and what you used, copies as plain text. Days passed and your longest run of days in a row are kept; a day missed costs nothing.

The claims, checked

Checked by a test that runs the box with no screen, kept with the source rather than shipped with the game. The same seed and the same strokes give the same box: three scenes, each run for 1,200 ticks with sand, water, lava, acid, liquid nitrogen, a dummy, a barrel and a lightning strike, end the same twice over, cell for cell and body for body, and a different seed gives a different box. A battery wired into a 70-cell pool lights the far end of salt water over six thousand times in five seconds, and pure water never. A rope holds an iron weight a hundred cells off the floor, and a rocket strapped to a crate lifts it 178 cells in two seconds; both survive a save. Every number on every element card is read from the same table the simulation runs on. All 64 entries in the test log are made to happen there, each from an empty box, and every scene and rig, left alone or with one stroke in a corner for a minute of its own time, fills none of them. Scripted strokes pass thirty days of work orders, and every order at both ends of its layouts, within the ration; the same strokes pass on the same tick twice, and no order passes on its own.

Credits

Big Shoulders Display by Patric King and IBM Plex Mono by IBM, both under the SIL Open Font License. Inspired by The Powder Toy, Sandboxels and People Playground. Every sound is synthesised in the browser.