Floor Is Lava projects moving lava onto the floor and runs a jumping game on top of it. The effect handles the timer, the calls (JUMP!, FASTER!, WINNER!) and the rocks. The players handle the jumping and decide who's out.
Before you start
- A projector aimed at the floor. It can sit on a table, shelf or tripod. It doesn't have to be mounted overhead.
- A dark room. The darker the room, the brighter the lava and the timer look.
- A light, matte floor, pale rug or white sheet. Dark or glossy floors show much less.
- A clear play area, with cables taped down and the projector outside the jump zone.
Set it up
- Aim the projector at the floor and open Floor Is Lava on the computer connected to it.
- If the projector is angled rather than pointing straight down, calibrate it first (see How to use this with a projector below).
- Choose a Game and set it up. For Shrinking Islands that means Players and Round length. For Lava River it's Rocks, River speed and Round length.
- Select Play Fullscreen, darken the room and adjust Brightness.
- Players start at the edge of the lava. In Shrinking Islands, the game counts down 3-2-1 while the first rocks rise, then calls JUMP!.
You'll know it worked when the countdown is readable from where the players stand, the rocks look round rather than oval, and nothing but black shows outside the lava.
How the games work
Shrinking Islands is musical chairs on lava. The floor starts crowded: during a 3-2-1 intro about three rocks per player rise one at a time, up to 18. Over the first three rounds the rocks thin out one by one, each cracking and shaking for 3 seconds before it sinks, until there's one rock fewer than players. Every few seconds a rock also cracks while a new one rises somewhere else, so anyone on a cracking rock has to jump. There are two of these swaps in a 20-second round and more in longer ones. Each round ends when the timer reaches zero: the last rock of the round sinks and the floor calls JUMP!. Once the warm-up is over, each round removes one rock, so every JUMP! leaves someone in the lava. When a single rock is left, it's gold, and the floor shows WINNER! for a few seconds before a new game starts on its own. With 5 players and 20-second rounds, the count goes 15, 11, 8, 4, 3, 2, 1 and a game takes a little over two minutes.
Lava River floats rocks from right to left in lanes that move at different speeds, and the lava drifts with them. Players cross or hop between moving rocks. Each time the timer reaches zero the floor calls FASTER! and the river speeds up, over six speeds in total.
Free Play keeps the rocks still with no timer. It suits your own rules, or just the look of lava on the floor.
What each control does
| Control | Range | What it changes |
|---|---|---|
| Brightness | 0–100 | Overall output. At 0 the display is black. |
| Game | Shrinking Islands, Lava River, Free Play | Which game runs. Changing it starts a new game. |
| Players | 2–13 | Shrinking Islands only. The game starts with about three rocks per player (8–18) and thins them to one fewer than the players over three rounds, then removes one per round. More players means a longer game. |
| Rocks | 0–12 | Lava River and Free Play. How many rocks are on the lava. On a small floor, fewer may fit. |
| Round length | 10–120 s | Seconds per round (Shrinking Islands) or between speed-ups (Lava River). Longer Shrinking Islands rounds have more mid-round rock swaps, and the whole game takes longer. |
| River speed | 25–200% | Lava River only. The starting drift speed. |
| Rock size | 50–150% | Size of each rock. Bigger rocks are easier for small children. |
| Show timer on the floor | on/off | Projects the countdown, round and calls. Rocks stay clear of it, except in Lava River with the timer in the Centre, where they drift underneath. |
| Timer position | Bottom, Top, Centre | Where on the picture the timer sits. |
| Countdown beeps | on/off | Ticks for the last three seconds, a buzzer on every jump and, in Shrinking Islands, a low thud whenever a rock starts cracking. Off by default. |
| Rock layout | 1–100 | Each number gives a different set of rock positions. |
| Style | Molten, Cracked, Cartoon, Blue Magic, Toxic Acid | The look and colour of the lava. |
| Flow speed | 0–200% | How fast the lava churns. 0% freezes it (the game still runs). |
| Lava size | 50–200% | Size of the swirls and crust. |
| Bubbling | 0–100% | How much the surface bubbles. |
| Alignment grid | on/off | Calibration squares for an angled projector. |
| Angle correction | 0–70% | Narrows the far edge so an angled projector's trapezoid lands as a rectangle. |
| Far edge | Top, Bottom, Left, Right of picture | The side of the picture that lands furthest from the projector. |
| Depth correction | 50–200% | Packs more lava along the throw. Raise it if rocks look stretched away from you. |
| Even out brightness | 0–100% | Dims the near end to match the dimmer far end. |
| Scale, position, Mirror horizontally, Flip vertically | Fit and orient the whole picture, including the timer. |
Changing Game, Players, Round length, Rocks, Rock size, Rock layout or the timer settings restarts the game from the beginning. Changing Far edge or Depth correction, or resizing the window, keeps the game running but moves the rocks. The lava look, Angle correction, Even out brightness and Placement change nothing about the game.
How to use this with a projector
Overhead, pointing straight down, needs no correction. Leave Angle correction at 0%.
Angled from a table, shelf or tripod is the common setup. Use the projector's own keystone first, then Angle correction for whatever is left. Both cost some resolution, so don't push either further than you need.
Off a mirror at about 45° in front of the lens gets a table-top projector close to an overhead picture. The picture comes out mirror-reversed, including the timer text, so turn on Mirror horizontally.
To calibrate an angled setup:
- Turn on Alignment grid.
- Set Far edge to the side of the picture that lands furthest from the projector.
- Raise Angle correction until the grid's side lines run parallel on the floor.
- Adjust Depth correction until the squares look square.
- If the near end is brighter, raise Even out brightness.
- Turn Alignment grid off.
Calibration is done when, standing where the players will be, the grid lines run parallel and the squares look square. The timer is drawn on the same corrected floor, so it squares up too.
Common setups
- Birthday party, 6–8 kids. Shrinking Islands, Players set to the number of kids, Round length 15–20 s, Countdown beeps on, Rock size 120%.
- Younger children. Shrinking Islands with Round length 30 s and Rock size 130–150%, or Free Play with 8–10 rocks and your own rules.
- Older kids. Lava River, River speed 125%, Round length 20 s, Rock size 80–100%.
- Narrow hallway. Lava River with the timer at Top or Bottom, so the rocks run the length of the hallway.
Troubleshooting
The rocks look like ovals. An angled projector is stretching the picture. Turn on Alignment grid and raise Depth correction until the squares look square.
The picture is wider at one end. Far edge is on the wrong side, or Angle correction is too low. With the grid on, check Far edge, then raise Angle correction until the sides run parallel.
No beeps. Countdown beeps is off by default, and the browser only plays sound after you've clicked on the page. Turn beeps on, then select Play Fullscreen; that click counts. Check the computer's volume and which speaker it plays through.
Fewer rocks than expected in Lava River or Free Play. The floor is too small to fit that many with gaps between them and space around the timer. Lower Rock size, move the timer to the top or bottom, or turn it off. (Shrinking Islands always places every rock a round needs, and makes them smaller on a crowded floor.)
The rocks are smaller than Rock size suggests in Shrinking Islands. With many players on a small floor, the effect makes the rocks smaller so every round still has the right number, with room for the next layout to rise between them. Fewer players, a bigger projected area, or moving the timer off the floor gives bigger rocks.
The game restarted. Changing a game setting starts a new game. Set up and calibrate before the players line up.
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Next steps
For something calmer after the game, try Koi Pond. Falling Snow uses the same projector on a wall or window.