Turbo Pudding

HelicornDev diary

What goes into one explosion

· The Turbo Pudding team · 5 min read

Greenfold Meadows on a bright green hill: Thistle, a white helicopter with orange stripes, green engine pods and a tall green tail fin with a white mark on it, flies close on the left, while just ahead of its nose a row of Bitumen Tanks goes up in balls of orange fire, with dark wrecks on the grass below, chunks of debris flying out and a shower of brass and silver cogs bursting into the air behind; small orange cone stacks dot the grass, and pink and white blossom trees line the hills

In Helicorn, Thistle, a retired seeding helicopter with a cannon bolted on, takes the Paver’s machines apart one by one, and every one of them goes out with a bang. It’s Wednesday, dev diary day, so this week we take a single bang apart, including the version that didn’t work.

The picture at the top is Greenfold Meadows, where a row of Bitumen Tanks is going up one after another as Thistle flies past. Behind the fire, a shower of brass and steel cogs, the Scrap every broken machine throws out, bursts into the air.

One bang, many layers

An explosion in Helicorn is a stack of small effects that start together and end at different times. First comes a flash, well under a tenth of a second long. Then the fireball swells to its full size in the first quarter of its life. For anything bigger than the smallest machines, a ring rolls out along the ground. Sparks fly, and chunks of the machine are thrown up. Each chunk bounces once, slides and stops, and the bigger blasts give some of them a trail of smoke. Billows of soot roll up. After that, a column of smoke rises, what’s left of the machine keeps burning for a few seconds, and a scorched crater stays on the ground.

Four sizes

Machines come in four sizes. Small is a Cone Stack: a fireball 1.6 meters across that lasts 0.3 seconds, 8 sparks, 3 bits of debris and a short puff of smoke. Medium is a Site Shed: 3.6 meters, 0.45 seconds, 10 sparks, 6 bits of debris, a smoke column for 3 seconds and a fire for 2. Large is a Bitumen Tank: 5 meters, 0.6 seconds, 12 sparks, 10 bits of debris, half of them trailing smoke, a smoke column for 5 seconds, a fire for 4 and two extra pops after the main bang.

Extra large is the Drum Mixer, the biggest part of an Asphalt Plant: a fireball 7.5 meters across that lasts 0.8 seconds, a second flash a tenth of a second after the first, 16 sparks, 16 bits of debris, all of them smoking, a dust ring, four extra pops, a smoke column for 7 seconds and a fire for 6.

Flying machines leave no fire or smoke column, and nothing burns on water.

Greenfold Meadows by a road bridge over a blue river: on the left, the remains of an asphalt plant burn in a cloud of orange fire and dark soot, with gray, yellow and orange chunks of debris flying out of it and dark broken slabs lying on the grass; Thistle, a white helicopter with orange stripes, green engine pods and a green tail fin, flies above the road on the right, a stream of gold and silver cogs pours up past the rotor toward a red barn on the hill, small pale flowers ring the grass at the foot of the bridge, and a yellow road sign stands in the lower left corner
Searched “helicopter game big explosions.” Asked and answered.

The white plate

The first version of the fireball had a hot white core and a glow that added its light on top of whatever was behind it. But most of Greenfold Meadows is bright green grass, and light added to bright green turns pale lime, then white. A big blast became a flat white and lime disk about 16 meters wide, with no fire visible at all.

So the fire changed. It’s orange from the very first frame, and half of the fireball is solid, orange cooling to a dark ember red, while only the other half glows. The soot is nearly black and comes in after 0.05 seconds. The rings kept their size but got dimmer. And the flash for each link in a chain used to be 2.2 times the blast’s reach, which, with reaches of 5 to 8 meters, turned the whole screen white. It’s 1.1 times now.

A setting called Reduce shake & flash cuts the flashes to 40 percent, the light on the ground to half and the camera shake to 30 percent, and turns off the short pauses below.

Rustrock Canyon, with tall red and orange cliffs on the left and a sandy floor: Thistle, the white helicopter with orange stripes and a green tail fin with a white mark on it, flies close on the left above a small yellow forklift carrying a blue crate, while white steel cogs and a green leaf-shaped bonus inside a glowing ring float just ahead of its nose; in the middle, a dark wreck on the road burns with a small orange fire inside a ring of warm light, a big silver and gold cog spins over the railway line on the right, a turquoise river crosses the far end of the canyon, and in the lower right corner an old scorched crater sits in a ring of tiny pale flowers
Typed “helicopter shooter desert.” The tank did not make it.

Chains, shakes and sound

Bitumen Tanks and Bitumen Kettles carry a blast of their own, and so does the Drum Mixer. When one goes up, its blast goes off 0.22 seconds later and hits everything around it, often another tank. The delay sends a ripple down the row instead of one big flash. When a whole row of depots goes up end to end, a gold ring rises over the last one in a spray of gold sparks, and a quick run of rising notes plays.

Camera shake grows with the square of a blast’s strength, so a small pop barely moves the picture and a big one really rattles it. When the fourth link of a chain goes off, the picture holds still for 0.04 seconds. A part torn off a boss holds it for 0.08, and a boss going down for 0.12.

The sound is built in layers too: a click, a body, a punch, a low rumble for the large ones, a crunch, little ticks of falling debris and the extra pops. No more than six explosions sound at once, and in a chain, each big blast that follows within half a second is 3 decibels quieter than the one before, down to 12 below.

What stays behind

A machine broken on the ground leaves its wreck and a crater, and the crater is scorched at once. Two and a half seconds later, a ring of flowers comes up around it. A whole mission leaves a line of fresh meadow cut right through the asphalt.

Greenfold Meadows from above: a diagonal line of charred black wrecks with yellow scraps of metal on top lies across the green grass, each in its own scorched patch ringed with tiny pink, white, blue and yellow flowers; Thistle, the white helicopter with orange stripes and a green tail fin, flies close on the right, and beyond the wrecks a crowd of brass and silver cogs tumbles through the air toward a glowing ring with a pinecone inside, with a winding road and a red barn at the top of the picture
People also ask: why are there flowers in the crater?

Fly the first world

World 1, Greenfold Meadows, is free to play in your browser at helicorn.com. The full game, all six worlds, is $4.99, paid once. More about the game is on its Helicorn page.

More about Helicorn

HelicornScreenshot Saturday

Helicorn: postcards from all six worlds

Blossom trees, red mesas, open sea, a snowy glacier, a foundry and an endless car park: one frame from each of Thistle’s six worlds.