smooth-bevy-cameras

A collection of exponentially-smoothed camera controllers for the Bevy Engine.

Look Transform

All controllers are based on a LookTransform component, which is just an eye point that looks at a target point. By modifying this component, the scene graph Transform will automatically be synchronized.

Any entities with {Transform, LookTransform, Smoother} components will automatically have their Transform smoothed. Smoothing will have no effect on the LookTransform, only the final Transform in the scene graph.

// Enables the system that synchronizes your `Transform`s and `LookTransform`s.
app.add_plugin(LookTransformPlugin);

...

commands
    .spawn_bundle(LookTransformBundle {
        transform: LookTransform { eye, target },
        smoother: Smoother::new(0.9), // Value between 0.0 and 1.0, higher is smoother.
    })
    .insert(PerspectiveCameraBundle::default())

...

fn move_camera_system(mut cameras: Query<&mut LookTransform>) {
    // Later, another system will update the `Transform` and apply smoothing automatically.
    for c in cameras.iter_mut() { c.target += Vec3::new(1.0, 1.0, 1.0); }
}

Look Angles

When implementing a camera controller, it's often useful to work directly with the angles (pitch and yaw) of your look direction. You can do this with the LookAngles type:

let mut angles = LookAngles::from_vector(transform.look_direction());
angles.add_pitch(delta.y);
angles.add_yaw(delta.x);
transform.target = transform.target + transform.radius() * angles.unit_vector();

This is how the built-in controllers implement rotation controls.

Built-In Controllers

These plugins depend on the LookTransformPlugin:

• FpsCameraPlugin + FpsCameraBundle
  • WASD: Translate on the XZ plane
  • Shift/Space: Translate along the Y axis
  • Mouse: Rotate camera
  • Run example : cargo run --release --example simple_fps
• OrbitCameraPlugin + OrbitCameraBundle
  • CTRL + mouse drag: Rotate camera
  • Right mouse drag: Pan camera
  • Mouse wheel: Zoom
  • Run example : cargo run --release --example simple_orbit
• UnrealCameraPlugin + UnrealCameraBundle
  • Left mouse drag: Locomotion
  • Right mouse drag: Rotate camera
  • Left and Right mouse drag: Pan camera
  • Run example : cargo run --release --example simple_unreal