# The camera > How the camera follows a unit, keeps clear of rocks and dives under the sea, the lens it looks through, and how speed, the booster and crashes reach it. In a third-person game the camera is half of how a unit feels. It decides what you see, how fast the World seems to move, and whether a crash lands like a blow or like a number. This page covers what Orbium's camera does today, the lens it looks through, and the work planned to make every action felt. The repository's own notes on it are in `CAMERA.md`. ## Over the shoulder During a window the camera rides a boom behind your unit and a little to its side, looking past its shoulder at what it faces (Walker.js (`client/src/game/Walker.js`), `placeCamera`). The boom is 6.4 m long and the vertical field of view is 62°. *Figure: The camera boom behind a unit, pulled in short of a rock that stands between the unit and where the camera wants to be* - **Keeping clear.** The boom never passes through the ground, a rock or the platform's deck. Each frame it is marched outwards from the unit's head in 0.25 m steps, and the first blocked step is bisected, so the camera slides smoothly along a slope instead of jumping a step at a time (`boomReach`). It pulls in quickly when something comes close and lets out slowly when it clears, so a rock passing behind you doesn't make the view pump. - **The shoulder.** The sideways offset is also checked, so the camera never slides into a rock beside the unit (`reach`). - **Height.** The camera follows the unit's height with a small dead zone and a short lag. Bumps and small hops don't shake the view, but the camera never falls more than 0.6 m behind. - **Looking up.** The more you look up, the shorter the boom, so the sky doesn't fill the screen with the unit as a speck. - **Under the sea.** When a unit dives, the camera goes under with it, crossing the surface in half a second, and the underwater lens takes over. Above the sea, it never drops into the waves (`seaCamera`). ## The long lens Holding zoom (right click, or LT on a gamepad) eases the field of view down to 24° and brings the camera in to the shoulder, with a heavier vignette and a little more grain, like a long lens (Game.js (`client/src/game/Game.js`), `lensTo`). The look slows by the same ratio, so a mouse movement turns the view by the same distance on screen either way. A rangefinder gives the distance to whatever the centre of the view is on. ## When you aren't driving - **Just down**: the camera stays where it was, easing back and up from the wreck while it watches it, then cuts to someone still in the window. - **Watching**: it orbits the watched unit, with the same boom that keeps clear of rocks. Switching units is a cut, not a swoop across the World. - **A window's close**: the camera cranes up and over to the unit that took the window and circles it, keeping clear of the ground and the rocks around it. The last moment plays in slow motion: the World, the units and any bolt still in flight drop to a fifth of their pace as the window closes and are back to full speed within two seconds. The camera's move itself keeps real time. ## Shake and knocks Every effect on the camera goes through one small rig (CameraRig.js (`client/src/game/CameraRig.js`)). Whatever placed the camera this frame leaves its pose, the rig adds its effects on top as the last thing before the World is drawn, and takes them off again before the next frame. The crosshair's aim is taken before the effects, so they never move it. - **Layers.** An effect sets its own share of the field of view, roll, vignette and grain each frame, and the rig adds them up over the plain lens. The long lens is one of them. - **Shake.** A crash, a hard landing, leaving the deck, a bolt fired or landing nearby, or a hit raises the camera's "trauma", between 0 and 1, which then falls away in under a second. The shake is trauma squared, so small bumps barely register and big ones hit hard. It mostly turns the camera (yaw, pitch and roll) rather than moving it, and it follows smooth noise rather than a new random offset each frame: it feels the same at 60 and 240 Hz, and the motion blur and the upscaler don't smear it. Zoomed in, the turn is scaled down so it is the same size on screen. - **Knocks.** A spring that pushes the camera one way and lets it settle back, with one soft overshoot. Crashing into a wall or ramming another unit knocks the view away from what it hit and rolls it away from that side, as hard as the crash was fast. - **Camera motion**, in the menu: Full, Reduced or Off, or Auto, which is Reduced when your system asks for reduced motion. It scales the shake, the knocks and anything else that moves the view. The long lens is your own, and isn't scaled. ## The lens The camera looks through the engine's post effects (PostFX.js (`engine/post/PostFX.js`)), several of which are about the camera itself rather than the World: - **Motion blur**, light on purpose: a third of the frame's time, so fast turns stay readable (MotionBlur.js (`engine/post/MotionBlur.js`)). It can be turned off in the menu. - **Auto exposure**, adapting like an eye when you look from the shade into the sky. - **Vignette and film grain**, faint, stronger on the long lens, and on the Medium and High presets a faint colour fringe toward the edges, as a real lens has. There is no barrel distortion: the name tags and the reticle are placed over the World by its plain projection, and a warped image would slide out from under them. - **A lens flare** facing the sun, **water drops** on the lens after the camera comes out of the sea or a jet's spray hits it, and **dust**: a booster's blast or a hard landing in sand or snow close by leaves soft, glowing specks out of focus and a faint film, which wear off in a few seconds and wash off in the sea (LensDroplets.js (`engine/post/LensDroplets.js`)). - **Heat shimmer** toward the horizon in the Desert. - **Cuts.** When the camera jumps (a cut to another unit) or turns sharply in a single frame, the post effects drop what they remember of the last frame, so the jump doesn't smear. ## Speed, the booster, crashes and hits What your unit does reaches the camera through the same rig (CameraFeel.js (`client/src/game/CameraFeel.js`)), eased so nothing snaps, and drawn on your machine alone: the server doesn't know about any of it. - **Speed.** The field of view widens with your speed, 6° wider at running speed, and less while you zoom. - **The boom.** It stretches back a little as you speed up, never into a rock behind you, closes in as you brake, and trails a little behind a sideways move, so your unit drifts off centre and settles back. - **The booster.** Its ignition punches the field of view 8° wider, fast in and slow out, and drops the view with a kick as the unit shoots up. It rumbles while it burns, and so do the drop's thrusters. In the last of the tank it sputters, the jolts coming faster as it empties. - **The water jets.** A burst surges your unit off, the view lagging behind it, and rumbles, harder under the water. At the surface it throws a rooster tail of white water, drops and mist behind you, and spatters the lens. Under it, the jets churn a milky plume of fine bubbles that billows, rises and thins away, with a stream of tiny ones and now and then a big one wobbling up, flattened into a cap. With Motion blur on, the burn opens the blur's shutter from a third of the frame to half of it. - **A speed blur.** Boosting at speed, with Motion blur on, the view streaks toward its centre at the edges, the centre kept sharp: six samples a pixel toward the middle, jittered so they don't band, and nothing while it's off. - **Banking.** In the air the view banks into your turns, up to about 4.6°. - **The ground under the wheels.** A faint, fast vibration by what you roll on and how fast: rough on rock and shingle, lighter on grass and the deck's plates, faint on sand and snow, none on ice. - **Landing.** The view dips by how far you fell, nods, and springs back. - **The Hunter's recoil.** Each bolt kicks the view up a little and narrows it by a degree, settled in about a tenth of a second, long before the next one. The bolt still goes where the crosshair was. - **Hit by a bolt.** The view is knocked away from the Hunter, and the lens pulses as it does in a crash. - **Worn down.** As your health falls, the view slowly loses its colour and closes in at the edges. - **A crash's pulse.** Besides the knock, the lens takes the blow: colour fringes toward the edges and a darker vignette for a moment, lit in the shield's light when your shield took it, washed of colour when it didn't. The hardest crashes muffle the sound for a moment too, through the same low-pass the sea uses. The fringe and the light are two uniforms in the final pass, skipped when they are zero: with them on, the pass measured the same. ## Close to the barrier The barrier is meant to look like it could hurt you, more the closer you come (Arena.js (`client/src/game/Arena.js`)): - **The field is never quiet.** Rings ripple out over it from a unit close to it, cells' outlines spark at random, more and more as it closes in, and its light flickers unevenly. Only the lines give light: the mesh holds still and you see through it between them. - **Its lines give off a shimmer.** In the final pass, each pixel's view ray is tested against the four walls of the barrier nearest the camera. Where it crosses one in front of the scene, the hex mesh is rebuilt there, and the image behind is pushed about just off the lines, fading toward the cells' middles, as if the lines were radiating. Nothing moves on a line itself, so the mesh stays put. It starts 45 m off the barrier and costs nothing further away. - **The camera picks up interference.** From 14 m in, grain and colour fringes rise and the view buzzes, finer and harder up to the touch. ## Game feel: what comes next > This part is a plan: the work below is being built and tuned in play. The goal is that what your unit does is felt, not just shown. What is left: ### The booster - **Heat haze** behind the nozzles. ### Polish - **Depth of field** for the shots where nobody aims: the wreck, a window's close, your unit in the Hold. ### Rules the effects keep - **Your aim stays true.** Effects move the view, never where you aim, and the look is never smoothed or delayed. The Hunter's shake stays small, and a recoil settles before the next bolt can fire. - **Steady at any frame rate**, as above. - **Light on the GPU.** Most effects are a setting or a few samples in the final pass. The ones that need a pass of their own, depth of field and heat haze, are measured before they ship.