Character camera

Target: Three.js 0.187.0 WebGPU. scripts/character-camera.js exports createCameraManager, createFirstPersonCamera and createThirdPersonCamera. They depend only on three/webgpu and on an input object that provides consumeMouseDelta() (see character-input).

Model

A camera manager owns the PerspectiveCamera and one active controller function (camera, dt) => void. The two controllers are factories that keep their own state (yaw and pitch) and return a bound controller when given the input and a target getter. Switching views is manager.setController(...); nothing else changes.

const manager = createCameraManager(camera, { fov: 75 });
const fp = createFirstPersonCamera({ sensitivity: 0.003 });
const tp = createThirdPersonCamera({ distance: 3, height: 0.5, sensitivity: 0.003 });
manager.setController(fp.bind(input, () => opts));            // first person
manager.setController(tp.bind(input, getAnchor, () => opts)); // third person
manager.update(dt); // once per frame, before the wish direction is computed

getAnchor returns the point the orbit looks at: the character's capsule centre plus 45 % of the model height from the feet (chest height), as a shared object.

First person

• Yaw and pitch in an Euler with order 'YXZ', applied as the camera quaternion.
• Pitch clamped to ±(π/2 − 0.01): looking straight up or down must not flip.
• Sensitivity 0.002–0.003 rad per pixel; invert is a sign on pitch only.
• Position is set by the wiring layer from the capsule: centre.y + eyeHeight − radius where eye height is 1.6 m standing, 0.9 m crouched, eased.
• The visible model is hidden in first person.

Third person

• Spherical orbit around a smoothed target: the target follows the anchor with a 16 /s exponential rate, which hides physics jitter without lag you can feel.
• Pitch range 0.1 to π/2 − 0.05 rad: never under the ground plane, never straight down.
• Distance 3 m default, scroll in 0.45 m steps between 1.2 and 14 m.
• Height 0.5 m above the anchor.
• Facing of the model follows the wish direction at 18 /s, not the camera, so the character turns to where it walks while the camera stays where the player left it.
• No collision with walls in this kit; if walls are common, cast a ray from target to camera and shorten the distance to the hit.

Switching views

Carry the yaw across: entering third person copies the first-person yaw into the orbit and sets the model facing to the camera forward; entering first person copies the orbit yaw back. The player never has to re-find the direction they were looking.

Vehicles and follow targets

To attach the camera to something else (a vehicle, a cutscene subject), replace the anchor getter and hide the model; aimOrbitBehind(subjectYaw) puts the orbit behind the subject with a 0.32 rad pitch. Restoring the player's anchor restores the view.

Pitfalls

• Consume the pointer delta exactly once per frame, in the camera update. Reading it elsewhere steals the look.
• Keep camera.up at +Y in the orbit and call lookAt after setting the position.
• Update the projection matrix only when the fov actually changes.