Playing
Swimming and diving
Walk into deep water and you start to swim. Dive, and the camera goes under the surface into NatureGL Water's underwater view, with sea grass, coral, fish schools and a humpback whale.
underwater scenario, 7 m down beside the humpback. The two fish schools travel with the whale; two more hang over the bommies.#From walking to swimming
You switch to swimming when the water under you is more than 1.45 m deep and your body is more than 1.2 m below the surface. You switch back to walking when the depth under you drops below 1.25 m. There is no key for it.
At the surface you float with your eyes just above the water. The HUD mode chip reads Swimming, and Diving once the camera is under water. A depth gauge appears on the left while you are submerged.
#Swim controls
| Input | Action |
|---|---|
| W A S D | Swim at 2.3 m/s. Under water you swim along the view direction, so look down to go deeper. |
| Shift (held) | Swim at 3.8 m/s |
| C or Ctrl (held) | Dive at 2.2 m/s |
| Space (held) | Rise at 2.2 m/s |
Under water there is a gentle buoyancy of 0.35 m/s, so you drift up when you stop. You can't go through the sea floor.
#What's down there
| Feature | Where it comes from |
|---|---|
| Caustics on the sand, reef, coral and sea grass | NatureGL Water's caustics.patch(material) |
| Underwater fog and light shafts | NatureGL Water's underwater pass. The game deepens the fog colour and sets the density to 0.021 /m so the floor reads 20 m down. |
| Sea-grass meadows | About 9 000 instanced strap-leaf clumps between 2 and 17 m deep, swaying with a slow surge (src/world/seagrass.js) |
| Coral | Four procedural types (staghorn, brain, sea fan, tube sponge) round the reef rocks, and big bommies along the whale's route (src/world/reef.js) |
| Fish | Schools over the reef and with the whale: 140 on low up to 600 on ultra (src/life/sea.js) |
| Humpback whale | Cruises the south-west drop-off |
| Marine snow | Drifting motes around the camera, drawn only under water (src/world/marineSnow.js) |
| Sand ripples | Shading and normal perturbation in the ground shader |
#Exposure under water
Above water the display exposure comes from NatureGL Sky's light meter. Under water that meter says nothing useful about the light down here, so IslandGame pins the display exposure close to 1.0 as the camera goes under. Every dive looks the same whatever the time of day. See Composing the libraries.
underwater scenario frames the whale from 21 m off its inshore flank, slightly ahead, tilted down to show the floor.