Struct PointerComponent 

pub struct PointerComponent {
    pub enabled: bool,
    /* private fields */
}

User-facing pointer component.

Attach this under the pose-driving part of the topology (for example a desktop camera rig transform, an XR camera, or a controller-driven transform). At init time the engine spawns and owns a child RayCastComponent, so authoring only needs to describe the pointer itself.

Fields

enabled: bool

Implementations

impl PointerComponent

pub fn new() -> Self

Examples found in repository

examples/pointer-events.rs (line 404)

fn main() {
    mittens_engine::example_support::ensure_model_assets();
    utils::logger::init();

    let world = engine::ecs::World::default();
    let mut universe = engine::Universe::new(world);

    use engine::ecs::component::{
        AmbientLightComponent, BackgroundColorComponent, Camera3DComponent, ColorComponent,
        DirectionalLightComponent, InputComponent, InputTransformModeComponent, PointerComponent,
        TransformComponent,
    };

    // Background.
    let bg = universe
        .world
        .add_component(BackgroundColorComponent::new());
    let bg_c = universe
        .world
        .add_component(ColorComponent::rgba(0.12, 0.12, 0.16, 1.0));
    let _ = universe.world.add_child(bg, bg_c);
    universe.add(bg);

    // Lighting.
    let ambient = universe
        .world
        .add_component(AmbientLightComponent::rgb(0.30, 0.30, 0.32));
    universe.add(ambient);

    let sun_t = universe
        .world
        .add_component(TransformComponent::new().with_position(2.0, 4.0, 3.0));
    let sun = universe
        .world
        .add_component(DirectionalLightComponent::new());
    let _ = universe.attach(sun_t, sun);
    universe.add(sun_t);

    // Camera + pointer rig.
    let input = universe
        .world
        .add_component(InputComponent::new().with_speed(3.0));
    let input_mode = universe.world.add_component(
        InputTransformModeComponent::forward_z()
            .with_fps_rotation()
            .with_roll_axis_y(),
    );
    let _ = universe.attach(input, input_mode);

    let cam_t = universe
        .world
        .add_component(TransformComponent::new().with_position(0.0, 0.5, 4.5));
    let cam = universe
        .world
        .add_component(Camera3DComponent::new().with_fov(70.0));
    let pointer = universe.world.add_component(PointerComponent::new());

    let _ = universe.attach(input, cam_t);
    let _ = universe.attach(cam_t, cam);
    let _ = universe.attach(cam, pointer);

    example_util::spawn_desktop_camera_controls_hint(&mut universe, cam_t);
    universe.add(input);

    // Scene root for all interactive objects.
    let scene = universe.world.add_component(TransformComponent::new());
    universe.add(scene);

    // --- LEFT: click-only cubes ---
    let click_group = universe
        .world
        .add_component(TransformComponent::new().with_position(-2.2, 0.0, 0.0));
    let _ = universe.attach(scene, click_group);

    for (i, dy) in [-0.55_f32, 0.0, 0.55].iter().enumerate() {
        spawn_click_cube(&mut universe, click_group, [0.0, *dy, 0.0]);
        let _ = i;
    }
    spawn_label(
        &mut universe,
        click_group,
        [-0.25, -1.05, 0.0],
        "click\ncycles color",
    );

    // --- MID: drag-only cube ---
    let drag_cube_root = universe
        .world
        .add_component(TransformComponent::new().with_position(0.0, 0.0, 0.0));
    let _ = universe.attach(scene, drag_cube_root);

    spawn_drag_cube(
        &mut universe,
        drag_cube_root,
        [0.0, 0.0, 0.0],
        [0.35, 0.85, 0.55, 1.0],
    );
    spawn_label(
        &mut universe,
        drag_cube_root,
        [-0.25, -0.80, 0.0],
        "drag\nto move",
    );

    // --- RIGHT: drag + click cube ---
    let both_root = universe
        .world
        .add_component(TransformComponent::new().with_position(2.2, 0.0, 0.0));
    let _ = universe.attach(scene, both_root);

    spawn_both_cube(&mut universe, both_root, [0.0, 0.0, 0.0]);
    spawn_label(
        &mut universe,
        both_root,
        [-0.30, -0.80, 0.0],
        "drag to move\nclick for color",
    );

    universe.systems.process_commands(
        &mut universe.world,
        &mut universe.visuals,
        &mut universe.render_assets,
        &mut universe.command_queue,
    );

    universe.enable_repl();
    engine::Windowing::run_app(universe).expect("Windowing failed");
}

examples/button-press.rs (line 498)

fn main() {
    mittens_engine::example_support::ensure_model_assets();
    utils::logger::init();

    let world = engine::ecs::World::default();
    let mut universe = engine::Universe::new(world);

    // Minimal lit scene + pointer raycaster.
    use engine::ecs::component::{
        AmbientLightComponent, BackgroundColorComponent, Camera3DComponent,
        DirectionalLightComponent, InputComponent, InputTransformModeComponent, PointerComponent,
        TransformComponent,
    };

    let bg = universe
        .world
        .add_component(BackgroundColorComponent::new());
    let bg_c = universe
        .world
        .add_component(engine::ecs::component::ColorComponent::rgba(
            0.92, 0.92, 0.96, 1.0,
        ));
    let _ = universe.world.add_child(bg, bg_c);
    universe.add(bg);

    let ambient = universe
        .world
        .add_component(AmbientLightComponent::rgb(0.35, 0.35, 0.35));
    universe.add(ambient);

    let sun_t = universe
        .world
        .add_component(TransformComponent::new().with_position(1.0, 1.0, 1.0));
    let sun = universe
        .world
        .add_component(DirectionalLightComponent::new());
    let _ = universe.attach(sun_t, sun);
    universe.add(sun_t);

    let input = universe
        .world
        .add_component(InputComponent::new().with_speed(2.5));
    let input_mode = universe.world.add_component(
        InputTransformModeComponent::forward_z()
            .with_fps_rotation()
            .with_roll_axis_y(),
    );
    let _ = universe.attach(input, input_mode);

    let rig_t = universe
        .world
        .add_component(TransformComponent::new().with_position(0.0, 0.0, 2.5));
    let _ = universe.attach(input, rig_t);

    let cam = universe
        .world
        .add_component(Camera3DComponent::new().with_far(600.0).with_fov(70.0));
    let _ = universe.attach(rig_t, cam);

    let pointer = universe.world.add_component(PointerComponent::new());
    let _ = universe.attach(cam, pointer);

    example_util::spawn_desktop_camera_controls_hint(&mut universe, rig_t);
    universe.add(input);

    // The button.
    let button_root = spawn_button(
        &mut universe,
        [0.0, 0.0, 0.0],
        [1.20, 0.45],
        ButtonBorder::new(0.025, 0.025, 0.025, 0.025),
        "click me",
        0.18,
        [0.15, 0.15, 0.20, 1.0],
        [0.85, 0.85, 0.92, 1.0],
    );

    // A small 3-cube stack to the left of the button for gizmo testing:
    //   [cyan]
    // [yellow][light brown]
    //
    // These live under an EditorComponent subtree so clicking attaches the editor gizmo.
    {
        use engine::ecs::component::{EditorComponent, TransformComponent};

        let editor_root = universe.world.add_component(EditorComponent::new());

        // Position the stack in world space (left of the button).
        let stack_root = universe
            .world
            .add_component(TransformComponent::new().with_position(-1.55, 0.0, 0.0));
        let _ = universe.attach(editor_root, stack_root);

        let cube = 0.22_f32;
        let gap = 0.04_f32;
        let step = cube + gap;
        let y_bottom = -0.5 * step;
        let y_top = 0.5 * step;
        let x_left = -0.5 * step;
        let x_right = 0.5 * step;

        let yellow = [1.0, 0.92, 0.22, 1.0];
        let light_brown = [0.80, 0.66, 0.46, 1.0];
        let cyan = [0.20, 0.95, 1.0, 1.0];

        let _bottom_left = spawn_raycastable_colored_cube(
            &mut universe,
            stack_root,
            [x_left, y_bottom, 0.0],
            [cube, cube, 0.06],
            yellow,
        );
        let _bottom_right = spawn_raycastable_colored_cube(
            &mut universe,
            stack_root,
            [x_right, y_bottom, 0.0],
            [cube, cube, 0.06],
            light_brown,
        );
        let _top = spawn_raycastable_colored_cube(
            &mut universe,
            stack_root,
            [0.0, y_top, 0.0],
            [cube, cube, 0.06],
            cyan,
        );

        universe.add(editor_root);
    }

    universe.add_signal_handler(
        engine::ecs::SignalKind::DragStart,
        button_root,
        button_press_handler,
    );
    universe.add_signal_handler(
        engine::ecs::SignalKind::DragEnd,
        button_root,
        button_press_handler,
    );

    universe.systems.process_commands(
        &mut universe.world,
        &mut universe.visuals,
        &mut universe.render_assets,
        &mut universe.command_queue,
    );

    universe.enable_repl();
    engine::Windowing::run_app(universe).expect("Windowing failed");
}

examples/gestures-and-gizmos.rs (line 117)

fn build_gestures_and_gizmos_scene(universe: &mut engine::Universe) -> Scene {
    use engine::ecs::component::{
        BackgroundColorComponent, BackgroundComponent, Camera3DComponent, ColorComponent,
        DirectionalLightComponent, InputComponent, InputTransformModeComponent, PointerComponent,
        RaycastableComponent, RenderableComponent, TransformComponent, TransformGizmoComponent,
    };
    use engine::graphics::BuiltinMeshType;
    use engine::graphics::primitives::{MaterialHandle, Renderable};

    let tri_mesh = universe.render_assets.get_mesh(BuiltinMeshType::Triangle2D);
    let cube_mesh = universe.render_assets.get_mesh(BuiltinMeshType::Cube);
    let tetra_mesh = universe
        .render_assets
        .get_mesh(BuiltinMeshType::Tetrahedron);

    // BackgroundColor { C.rgba }
    let bg_color = universe
        .world
        .add_component(BackgroundColorComponent::new());
    let bg_color_c = universe
        .world
        .add_component(ColorComponent::rgba(0.90, 0.90, 0.90, 1.0));
    let _ = universe.world.add_child(bg_color, bg_color_c);
    universe.add(bg_color);

    // ambient light
    let ambient = universe
        .world
        .add_component(AmbientLightComponent::rgb(0.25, 0.25, 0.25));
    universe.add(ambient);

    // ground plane
    let ground_tx = universe.world.add_component(
        TransformComponent::new()
            .with_position(0.0, -2.5, 0.0)
            .with_scale(20.0, 1.0, 20.0),
    );
    let ground_r = universe
        .world
        .add_component(RenderableComponent::new(Renderable::new(
            universe.render_assets.get_mesh(BuiltinMeshType::Cube),
            MaterialHandle::TOON_MESH,
        )));
    let ground_c = universe
        .world
        .add_component(ColorComponent::rgba(0.75, 0.75, 0.75, 1.0));
    let _ = universe.attach(ground_tx, ground_r);
    let _ = universe.attach(ground_r, ground_c);
    let _ = universe.add(ground_tx);

    // Background {
    //     with_occlusion_and_lighting()
    //     // using the example utils to add clouds to the background
    // }
    let bg_root = universe
        .world
        .add_component(BackgroundComponent::new().with_occlusion_and_lighting());
    universe.add(bg_root);

    // DirectionalLight {
    //     T { translate [1, 1, 1] }
    // }
    // Directional lights encode their direction in the node's world position.
    let sun_t = universe
        .world
        .add_component(TransformComponent::new().with_position(1.0, 1.0, 1.0));
    let sun = universe
        .world
        .add_component(DirectionalLightComponent::new());
    let _ = universe.attach(sun_t, sun);
    universe.add(sun_t);

    // i = input
    // t = transform
    // c3d = camera3d
    //
    // I {
    //     T {
    //         C3D { with_fps_rotation().with_roll_axis_y() }
    //     }
    // }
    let input = universe
        .world
        .add_component(InputComponent::new().with_speed(2.5));
    let input_mode = universe.world.add_component(
        InputTransformModeComponent::forward_z()
            .with_fps_rotation()
            .with_roll_axis_y(),
    );

    let _ = universe.attach(input, input_mode);

    // Forward is -Z, so put the camera at +Z looking toward the origin.
    let rig_t = universe
        .world
        .add_component(TransformComponent::new().with_position(0.0, 0.0, 3.5));
    let _ = universe.attach(input, rig_t);

    let cam = universe
        .world
        .add_component(Camera3DComponent::new().with_far(600.0).with_fov(70.0));
    let _ = universe.attach(rig_t, cam);

    // Opt-in: treat this camera rig as a pointer source.
    let pointer = universe.world.add_component(PointerComponent::new());
    let _ = universe.attach(cam, pointer);

    // Topology: I { T { C3D } } — add a small camera-attached controls hint.
    example_util::spawn_desktop_camera_controls_hint(universe, rig_t);

    fn spawn_shape_with_gizmo(
        universe: &mut engine::Universe,
        mesh: engine::graphics::primitives::CpuMeshHandle,
        pos: [f32; 3],
        scale: [f32; 3],
        rot_euler: [f32; 3],
        color: [f32; 4],
    ) {
        let t = universe.world.add_component(
            TransformComponent::new()
                .with_position(pos[0], pos[1], pos[2])
                .with_scale(scale[0], scale[1], scale[2])
                .with_rotation_euler(rot_euler[0], rot_euler[1], rot_euler[2]),
        );
        let r = universe
            .world
            .add_component(RenderableComponent::new(Renderable::new(
                mesh,
                MaterialHandle::TOON_MESH,
            )));
        let c = universe
            .world
            .add_component(ColorComponent::rgba(color[0], color[1], color[2], color[3]));
        let rc = universe
            .world
            .add_component(RaycastableComponent::enabled());
        let g = universe.world.add_component(TransformGizmoComponent::new());

        let _ = universe.attach(t, r);
        let _ = universe.attach(r, c);
        let _ = universe.attach(r, rc);
        let _ = universe.attach(t, g);

        universe.add(t);
    }

    fn spawn_shape_raycastable_no_gizmo(
        universe: &mut engine::Universe,
        mesh: engine::graphics::primitives::CpuMeshHandle,
        pos: [f32; 3],
        scale: [f32; 3],
        rot_euler: [f32; 3],
        color: [f32; 4],
    ) {
        let t = universe.world.add_component(
            TransformComponent::new()
                .with_position(pos[0], pos[1], pos[2])
                .with_scale(scale[0], scale[1], scale[2])
                .with_rotation_euler(rot_euler[0], rot_euler[1], rot_euler[2]),
        );
        let r = universe
            .world
            .add_component(RenderableComponent::new(Renderable::new(
                mesh,
                MaterialHandle::TOON_MESH,
            )));
        let c = universe
            .world
            .add_component(ColorComponent::rgba(color[0], color[1], color[2], color[3]));
        let rc = universe
            .world
            .add_component(RaycastableComponent::enabled());

        let _ = universe.attach(t, r);
        let _ = universe.attach(r, c);
        let _ = universe.attach(r, rc);

        universe.add(t);
    }

    spawn_shape_with_gizmo(
        universe,
        tri_mesh,
        [-1.2, 0.0, 0.0],
        [0.65, 0.65, 0.65],
        [0.0, 0.0, 0.0],
        [0.2, 0.9, 0.25, 1.0],
    );
    spawn_shape_with_gizmo(
        universe,
        cube_mesh,
        [0.0, 0.0, 0.0],
        [0.55, 0.55, 0.55],
        [0.0, 0.0, 0.0],
        [0.95, 0.25, 0.2, 1.0],
    );
    spawn_shape_with_gizmo(
        universe,
        tetra_mesh,
        [1.2, 0.0, 0.0],
        [0.7, 0.7, 0.7],
        [0.0, 0.0, 0.0],
        [0.2, 0.55, 1.0, 1.0],
    );

    // Standalone tetrahedron: no gizmo, but explicitly raycastable.
    // This helps isolate tetra picking vs gizmo-handle interception.
    spawn_shape_raycastable_no_gizmo(
        universe,
        tetra_mesh,
        [2.6, -0.6, 0.0],
        [0.95, 0.95, 0.95],
        [0.0, 0.0, 0.0],
        [0.85, 0.85, 1.0, 1.0],
    );

    universe.add(input);

    Scene { bg_root }
}

examples/vr-input.rs (line 278)

fn main() {
    mittens_engine::example_support::ensure_model_assets();
    utils::logger::init();

    let options = match parse_options() {
        Ok(options) => options,
        Err(message) => {
            eprintln!("{message}");
            std::process::exit(2);
        }
    };

    println!(
        "[vr-input] xr controller rotation filter pipeline: {}",
        if options.xr_controller_rotation_filter {
            "enabled"
        } else {
            "disabled"
        }
    );

    let world = engine::ecs::World::default();
    let mut universe = engine::Universe::new(world);

    let renderer_settings = universe
        .world
        .add_component(RendererSettingsComponent::msaa_off().with_window_size(320, 240));
    universe.add(renderer_settings);

    let render_graph = universe.world.add_component(RenderGraphComponent::new());
    let emissive_pass = universe.world.add_component(EmissivePassComponent::new());
    let blur_pass = universe.world.add_component(
        BlurPassComponent::new()
            .with_radius_ndc(0.06)
            .with_half_res(true),
    );
    let bloom = universe.world.add_component(
        BloomComponent::new()
            .with_intensity(0.95)
            .with_emissive_scale(1.2),
    );
    let _ = universe.attach(emissive_pass, blur_pass);
    let _ = universe.attach(render_graph, emissive_pass);
    let _ = universe.attach(render_graph, bloom);
    universe.add(render_graph);

    // Sky base.
    let background = universe
        .world
        .add_component(BackgroundColorComponent::new());
    let background_c = universe
        .world
        .add_component(ColorComponent::rgba(0.62, 0.80, 1.00, 1.0));
    let _ = universe.world.add_child(background, background_c);
    universe.add(background);

    // Lighting for the model.
    let ambient = universe
        .world
        .add_component(AmbientLightComponent::rgb(0.18, 0.18, 0.22));
    universe.add(ambient);

    let sun = universe.world.add_component(
        DirectionalLightComponent::new()
            .with_intensity(1.1)
            .with_color(1.0, 0.98, 0.95),
    );
    let sun_dir = universe
        .world
        .add_component(TransformComponent::new().with_position(0.15, -0.45, 1.0));
    let _ = universe.attach(sun_dir, sun);
    universe.add(sun_dir);

    // --- Desktop camera rig (for debugging while in VR) ---
    let input = universe
        .world
        .add_component(InputComponent::new().with_speed(1.5));
    let input_mode = universe.world.add_component(
        InputTransformModeComponent::forward_z()
            .with_fps_rotation()
            .with_roll_axis_y(),
    );
    let _ = universe.attach(input, input_mode);

    let desktop_rig = universe
        .world
        .add_component(TransformComponent::new().with_position(0.0, 1.2, 3.5));
    let _ = universe.attach(input, desktop_rig);

    let camera3d = universe.world.add_component(Camera3DComponent::new());
    let _ = universe.attach(desktop_rig, camera3d);

    let pointer = universe.world.add_component(PointerComponent::new());
    let _ = universe.attach(camera3d, pointer);

    example_util::spawn_desktop_camera_controls_hint(&mut universe, desktop_rig);
    universe.add(input);

    // --- XR rig (Aim controller debug cubes only; camera has moved to AVC) ---
    let xr_input = universe.world.add_component(InputXRComponent::on());
    let xr_gamepad = universe.world.add_component(
        mittens_engine::engine::ecs::component::InputXRGamepadComponent::new().speed(1.5),
    );
    let xr_rig = universe.world.add_component(TransformComponent::new());
    let _ = universe.attach(xr_input, xr_rig);
    let _ = universe.attach(xr_input, xr_gamepad);

    // renderer stats
    let renderer_stats = universe
        .world
        .add_component(RendererStatsComponent::new().with_camera_target(CameraTarget::Xr));
    let render_stats_rig = universe
        .world
        .add_component(TransformComponent::new().with_position(0.0, 1.85, 0.6));
    let _ = universe.attach(render_stats_rig, renderer_stats);
    let _ = universe.attach(xr_rig, render_stats_rig);

    universe.add(xr_input);

    // Background "skybox" content.
    spawn_sun_background(&mut universe);

    // --- VTuber model — single-input topology ---
    //
    // InputXRComponent drives body translation and head rotation through AvatarControlSystem.
    // AvatarControlSystem:
    //   - Splices a TransformComponent under J_Bip_C_Head's parent (the neck) to drive
    //     head rotation directly. Rotating the head — not the neck — isolates the spine
    //     so the torso doesn't twist with HMD yaw.
    //   - Strips rotation from model_root (body faces body_yaw, not raw HMD yaw).
    //   - Bakes the π Y handedness correction into the head rotation math.
    //   - Smoothly rotates body to follow head when yaw delta exceeds threshold.
    //   - Measures J_Bip_C_Head local Y in the rest pose and sets model_root.y = -bone_local_y,
    //     so the head bone sits at driven_t world Y (= HMD height) with no hardcoded constant.
    //   - Re-parents CameraXRComponent under J_Bip_C_Head for first-person alignment.
    //
    // Topology (after AVC init):
    //   editor_root
    //     └── avatar_input_xr (InputXRComponent)
    //           └── avatar_driven_t (TransformComponent)
    //                 └── AvatarControlComponent
    //                       ├── body_pipeline → pipeline_output
    //                       │     └── model_root (y auto-calibrated from J_Bip_C_Head)
    //                       │           └── GLTFComponent → ... → J_Bip_C_Head
    //                       │                                           └── CameraXRComponent
    //                       ├── CTLXR(Left, Grip) → re-parented to lower_arm
    //                       └── CTLXR(Right, Grip) → re-parented to lower_arm

    let editor_root = universe.world.add_component(EditorComponent::new());

    let avatar_input_xr = universe.world.add_component(InputXRComponent::on());
    let avatar_xr_gamepad = universe.world.add_component(
        mittens_engine::engine::ecs::component::InputXRGamepadComponent::new().speed(1.5),
    );
    let avatar_driven_t = universe.world.add_component(TransformComponent::new());
    let _ = universe.attach(avatar_input_xr, avatar_driven_t);
    let _ = universe.attach(avatar_input_xr, avatar_xr_gamepad);

    // AvatarControlComponent: -Z forward (OpenXR default), body starts facing -Z (π yaw).
    // camera_bone triggers auto-calibration of model_root.y from J_Bip_C_Head rest pose height,
    // and causes any CameraXR/Camera3D direct children of AVC to be re-parented to that bone.
    let avatar_control = universe.world.add_component(
        AvatarControlComponent::new()
            .with_head_bone("J_Bip_C_Head")
            .with_camera_bone("J_Bip_C_Head")
            .with_left_hand_bone("J_Bip_L_Hand")
            .with_right_hand_bone("J_Bip_R_Hand")
            .with_initial_yaw(std::f32::consts::PI)
            .with_hand_rotation_smoothing(220.0),
    );
    let _ = universe.attach(avatar_driven_t, avatar_control);

    // CameraXR as a direct child of AVC — discovered and re-parented to J_Bip_C_Head at init.
    let camera_xr = universe.world.add_component(CameraXRComponent::on());
    let _ = universe.attach(avatar_control, camera_xr);
    let head_pointer = universe.world.add_component(PointerComponent::new());
    let _ = universe.attach(camera_xr, head_pointer);

    // Grip controllers for hand bone splicing — children of AvatarControlComponent so
    // AvatarControlSystem discovers them by topology. Each needs a TransformComponent
    // child (driven_t) that OpenXRSystem writes each tick.
    let left_grip = universe.world.add_component(ControllerXRComponent::new(
        true,
        ControllerHand::Left,
        ControllerPoseKind::Grip,
    ));
    let left_grip_t = universe.world.add_component(TransformComponent::new());
    let _ = universe.attach(left_grip, left_grip_t);
    let left_pointer = universe.world.add_component(PointerComponent::new());
    let _ = universe.attach(left_grip_t, left_pointer);
    let _ = universe.attach(avatar_control, left_grip);

    let right_grip = universe.world.add_component(ControllerXRComponent::new(
        true,
        ControllerHand::Right,
        ControllerPoseKind::Grip,
    ));
    let right_grip_t = universe.world.add_component(TransformComponent::new());
    let _ = universe.attach(right_grip, right_grip_t);
    let right_pointer = universe.world.add_component(PointerComponent::new());
    let _ = universe.attach(right_grip_t, right_pointer);
    let _ = universe.attach(avatar_control, right_grip);

    // model_root: no explicit Y offset — AvatarControlSystem calibrates it from J_Bip_C_Head.
    let model_root = universe.world.add_component(TransformComponent::new());
    let model = universe
        .world
        .add_component(GLTFComponent::new("assets/models/pc-rei.hoodie.glb"));
    let emissive = universe.world.add_component(EmissiveComponent::on());
    let _ = universe.attach(model, emissive);

    let _ = universe.attach(editor_root, avatar_input_xr);
    let _ = universe.attach(avatar_control, model_root);
    let _ = universe.attach(model_root, model);
    universe.add(editor_root);

    // --- Controller debug cubes (tracked poses) ---
    let _left = spawn_controller_cube(
        &mut universe,
        xr_rig,
        ControllerHand::Left,
        (0.10, 0.90, 1.00, 1.0),
        220.0,
        options.xr_controller_rotation_filter,
    );
    let _right = spawn_controller_cube(
        &mut universe,
        xr_rig,
        ControllerHand::Right,
        (1.00, 0.35, 0.35, 1.0),
        220.0,
        options.xr_controller_rotation_filter,
    );

    // Enable OpenXR runtime.
    let xr_root = universe.world.add_component(XrComponent::on());
    universe.add(xr_root);

    universe.systems.process_commands(
        &mut universe.world,
        &mut universe.visuals,
        &mut universe.render_assets,
        &mut universe.command_queue,
    );

    // Force the glTF subtree to spawn so we can query the armature for bone markers.
    {
        let systems = &mut universe.systems;
        systems.gltf.tick_with_queue(
            &mut universe.world,
            &mut universe.visuals,
            &mut systems.skinned_mesh,
            &mut universe.command_queue,
            0.0,
        );
    }
    universe.systems.process_commands(
        &mut universe.world,
        &mut universe.visuals,
        &mut universe.render_assets,
        &mut universe.command_queue,
    );

    // Bone markers for editor inspection.
    let marker_joints: &[(&str, (f32, f32, f32, f32))] = &[
        ("[name='J_Bip_C_Head']", (0.85, 0.20, 0.85, 0.9)),
        ("[name='J_Bip_C_Neck']", (0.20, 0.85, 0.85, 0.9)),
        ("[name='J_Bip_C_UpperChest']", (0.20, 0.20, 0.85, 0.9)),
        ("[name='J_Bip_L_UpperArm']", (0.85, 0.85, 0.20, 0.9)),
        ("[name='J_Bip_R_UpperArm']", (0.85, 0.60, 0.20, 0.9)),
    ];

    for &(selector, color) in marker_joints {
        let Some(bone) = universe.find_component(model_root, selector) else {
            continue;
        };
        let marker_t = universe
            .world
            .add_component(TransformComponent::new().with_scale(0.025, 0.025, 0.025));
        let marker_r = universe.world.add_component(RenderableComponent::cube());
        let marker_c = universe
            .world
            .add_component(ColorComponent::rgba(color.0, color.1, color.2, color.3));
        let marker_rcast = universe
            .world
            .add_component(RaycastableComponent::enabled());
        let _ = universe.world.add_child(marker_r, marker_c);
        let _ = universe.world.add_child(marker_r, marker_rcast);
        let _ = universe.world.add_child(marker_t, marker_r);
        let _ = universe.attach(bone, marker_t);
    }

    universe.enable_repl();
    engine::Windowing::run_app(universe).expect("Windowing failed");
}

examples/font-example.rs (line 83)

fn main() {
    mittens_engine::example_support::ensure_model_assets();
    utils::logger::init();

    let world = engine::ecs::World::default();
    let mut universe = engine::Universe::new(world);

    // Dark background so the font texture pops.
    let background = universe
        .world
        .add_component(BackgroundColorComponent::new());
    let background_c = universe
        .world
        .add_component(ColorComponent::rgba(0.20, 0.2, 0.20, 1.0));
    let _ = universe.world.add_child(background, background_c);
    universe.add(background);

    // Ambient so text is readable even without explicit lights.
    let ambient = universe
        .world
        .add_component(AmbientLightComponent::rgb(0.50, 0.50, 0.50));
    universe.add(ambient);

    let directional_tx = universe
        .world
        .add_component(TransformComponent::new().with_position(0.0, 0.5, 1.0));
    let directional_light = universe.world.add_component(
        engine::ecs::component::DirectionalLightComponent::new()
            .with_color(1.0, 1.0, 1.0)
            .with_intensity(0.8),
    );
    let _ = universe.attach(directional_tx, directional_light);
    universe.add(directional_tx);

    // --- background clouds ---
    // Background stage (occluded + lit) so the cloud volume self-occludes but won't occlude
    // the foreground text (renderer clears depth before foreground).
    let bg_root = universe
        .world
        .add_component(BackgroundComponent::new().with_occlusion_and_lighting());
    universe.add(bg_root);

    let mut bg_cloud_params = example_util::CloudRingParams::default();
    bg_cloud_params.cloud_count = 6;
    bg_cloud_params.seed = 0xF0_17_C10u32;
    example_util::spawn_cloud_ring(&mut universe, bg_root, bg_cloud_params);

    // I {
    //   // not fps rotation, just relative rotation
    //   with_forward_z()
    //   with_roll_axis_y()
    //   C3D {}
    // }
    let input = universe
        .world
        .add_component(InputComponent::new().with_speed(2.0));
    let input_mode = universe
        .world
        .add_component(InputTransformModeComponent::forward_z().with_roll_axis_y());
    let _ = universe.attach(input, input_mode);

    let rig_transform = universe
        .world
        .add_component(TransformComponent::new().with_position(1.8, -0.5, 2.5));
    let _ = universe.attach(input, rig_transform);

    let camera = universe.world.add_component(Camera3DComponent::new());
    let _ = universe.attach(rig_transform, camera);

    // Click-to-pick: treat this camera rig as a pointer source.
    let pointer = universe.world.add_component(PointerComponent::new());
    let _ = universe.attach(camera, pointer);

    // Topology: I { T { C3D } } — add a small camera-attached controls hint.
    example_util::spawn_desktop_camera_controls_hint(&mut universe, rig_transform);

    universe.add(input);

    // --- foreground clouds ---
    // Normal foreground renderables (not background stage).
    // Offset the ring forward (negative Z) so several clusters are in view.
    let fg_cloud_root = universe
        .world
        .add_component(TransformComponent::new().with_position(0.0, -6.0, -10.0));
    universe.add(fg_cloud_root);

    let mut fg_cloud_params = example_util::CloudRingParams::default();
    fg_cloud_params.cloud_count = 4;
    fg_cloud_params.radius = 9.0;
    fg_cloud_params.center_y = 1.0;
    fg_cloud_params.puffs_per_cloud = 22;
    fg_cloud_params.angle_jitter = 0.35;
    fg_cloud_params.high_y_probability = 0.35;
    fg_cloud_params.high_y_multiplier = 1.4;
    fg_cloud_params.seed = 0xF0_17_C102u32;
    example_util::spawn_cloud_ring(&mut universe, fg_cloud_root, fg_cloud_params);

    // T {
    //   with_translation(0,0, -2)
    //   TXT {
    //     "ababaabbaabbaaabbbaaabbbaaaabbbbaaaaabbbbbababababa"
    //     TextureComponent { assets/images/test.font_system.png }
    //   }
    // }
    fn estimate_text_height_world(text: &str, scale: f32) -> f32 {
        let line_count = text.lines().count().max(1) as f32;
        // Text quads are ~1 unit tall per line in text-space.
        // Add some padding so blocks don't feel cramped.
        let pad_lines = 1.25;
        (line_count + pad_lines) * scale
    }

    fn spawn_text_block(
        universe: &mut engine::Universe,
        position: (f32, f32, f32),
        scale: f32,
        text: &str,
        font_texture_uri: Option<&str>,
        text_color_rgba: Option<[f32; 4]>,
        shadow: Option<TextShadowComponent>,
        filtering: TextureFilteringComponent,
    ) -> f32 {
        // T_root { T_scale { [Color] { TXT { shadow, filtering } } } }
        let text_root = universe.world.add_component(
            TransformComponent::new().with_position(position.0, position.1, position.2),
        );

        let text_scale = universe
            .world
            .add_component(TransformComponent::new().with_scale(scale, scale, 1.0));
        let _ = universe.attach(text_root, text_scale);

        let text_parent = if let Some([r, g, b, a]) = text_color_rgba {
            let color = universe
                .world
                .add_component(ColorComponent::rgba(r, g, b, a));
            let _ = universe.attach(text_scale, color);
            color
        } else {
            text_scale
        };

        let text_c = universe.world.add_component(TextComponent::new(text));
        let _ = universe.attach(text_parent, text_c);

        // Explicit opt-in: make the glyph renderables pickable.
        // TextSystem will propagate this to all spawned glyph quads.
        let raycastable = universe
            .world
            .add_component(RaycastableComponent::enabled());
        let _ = universe.attach(text_c, raycastable);

        // Route glyph quads into the alpha-to-coverage cutout pass.
        let cutout = universe
            .world
            .add_component(TransparentCutoutComponent::new());
        let _ = universe.attach(text_c, cutout);

        if let Some(shadow) = shadow {
            let shadow_id = universe.world.add_component(shadow);
            let _ = universe.attach(text_c, shadow_id);
        }

        // Optional: override the font atlas for this text block.
        // TextSystem will propagate this to all glyph renderables.
        if let Some(uri) = font_texture_uri {
            let tex = universe
                .world
                .add_component(TextureComponent::with_uri(uri));
            let _ = universe.attach(text_c, tex);
        }

        let filtering_id = universe.world.add_component(filtering);
        let _ = universe.attach(text_c, filtering_id);

        universe.add(text_root);

        estimate_text_height_world(text, scale)
    }

    // --- text blocks ---
    // Multi-line samples at different scales.
    // (Text literals omitted in the README/snippet; see constants below.)
    const TEXT_BIG: &str = "CAT ENGINE\nfont example\nBIG TEXT";
    const TEXT_MED: &str = "multi-line\ntext block\nmedium";
    const TEXT_SMALL: &str = "small\ntext";
    const TEXT_TINY: &str = "tiny\ntext\n(zoom in)";

    // Stack vertically; advance by (measured height + gap) so big text gets more room.
    let x = -1.2;
    let z = -2.0;
    let mut y = 1.2;
    let gap = 0.15;

    let shadow_crisp = Some(
        TextShadowComponent::new()
            .with_scale(1.35)
            .with_offset([0.06, -0.06, 0.0015]),
    );

    y -= spawn_text_block(
        &mut universe,
        (x, y, z),
        0.55,
        TEXT_BIG,
        None,
        Some([1.0, 1.0, 1.0, 1.0]),
        shadow_crisp,
        TextureFilteringComponent::nearest_magnification(),
    ) + gap;
    y -= spawn_text_block(
        &mut universe,
        (x, y, z),
        0.25,
        TEXT_MED,
        None,
        Some([0.60, 0.95, 1.00, 1.0]),
        Some(
            TextShadowComponent::new()
                .with_rgba([0.0, 0.0, 0.15, 1.0])
                .with_scale(1.20)
                .with_offset([0.05, -0.04, 0.0015]),
        ),
        TextureFilteringComponent::linear(),
    ) + gap;
    y -= spawn_text_block(
        &mut universe,
        (x, y, z),
        0.14,
        TEXT_SMALL,
        None,
        Some([1.0, 0.88, 0.35, 1.0]),
        Some(
            TextShadowComponent::new()
                .with_rgba([0.15, 0.0, 0.0, 1.0])
                .with_scale(1.55)
                .with_offset([0.08, -0.08, 0.0015]),
        ),
        TextureFilteringComponent::nearest(),
    ) + gap;
    let _ = spawn_text_block(
        &mut universe,
        (x, y, z),
        0.08,
        TEXT_TINY,
        None,
        Some([0.90, 1.0, 0.70, 1.0]),
        shadow_crisp,
        TextureFilteringComponent::nearest_magnification(),
    );

    // Left block: explicit multi-line text using the default font_system atlas.
    const TEXT_LEFT: &str = "even though there's hexes\nto the solar plexus in my lexus\ni'm feelin' reckless,\nwhen i'm eating breakfast";
    let _ = spawn_text_block(
        &mut universe,
        (x - 8.1, 1.1, z),
        0.22,
        TEXT_LEFT,
        Some("assets/textures/font_system.dds"),
        Some([0.95, 0.95, 0.95, 1.0]),
        Some(
            TextShadowComponent::new()
                .with_scale(1.25)
                .with_offset([0.05, -0.05, 0.0015]),
        ),
        TextureFilteringComponent::nearest_magnification(),
    );

    // Alt atlas: put it *behind* the original stack (slightly farther from the camera)
    // and tint it dark grey.
    let alt_atlas = Some("assets/textures/font_system.0.0.dds");
    let alt_z = z - 0.05;
    let alt_grey = Some([0.25, 0.25, 0.25, 1.0]);

    let mut y_alt = 1.2;
    y_alt -= spawn_text_block(
        &mut universe,
        (x, y_alt, alt_z),
        0.55,
        TEXT_BIG,
        alt_atlas,
        alt_grey,
        Some(
            TextShadowComponent::new()
                .with_rgba([0.0, 0.0, 0.0, 1.0])
                .with_scale(1.15)
                .with_offset([0.03, -0.03, 0.0015]),
        ),
        TextureFilteringComponent::linear(),
    ) + gap;
    y_alt -= spawn_text_block(
        &mut universe,
        (x, y_alt, alt_z),
        0.25,
        TEXT_MED,
        alt_atlas,
        alt_grey,
        Some(
            TextShadowComponent::new()
                .with_rgba([0.0, 0.0, 0.0, 1.0])
                .with_scale(1.15)
                .with_offset([0.03, -0.03, 0.0015]),
        ),
        TextureFilteringComponent::linear(),
    ) + gap;
    y_alt -= spawn_text_block(
        &mut universe,
        (x, y_alt, alt_z),
        0.14,
        TEXT_SMALL,
        alt_atlas,
        alt_grey,
        Some(
            TextShadowComponent::new()
                .with_rgba([0.0, 0.0, 0.0, 1.0])
                .with_scale(1.15)
                .with_offset([0.03, -0.03, 0.0015]),
        ),
        TextureFilteringComponent::linear(),
    ) + gap;
    let _ = spawn_text_block(
        &mut universe,
        (x, y_alt, alt_z),
        0.08,
        TEXT_TINY,
        alt_atlas,
        alt_grey,
        Some(
            TextShadowComponent::new()
                .with_rgba([0.0, 0.0, 0.0, 1.0])
                .with_scale(1.15)
                .with_offset([0.03, -0.03, 0.0015]),
        ),
        TextureFilteringComponent::linear(),
    );

    universe.enable_repl();

    let xr_input = universe.world.add_component(InputXRComponent::on());
    let xr_gamepad = universe
        .world
        .add_component(engine::ecs::component::InputXRGamepadComponent::new().speed(1.5));
    let xr_head = universe.world.add_component(TransformComponent::new());
    let xr_camera = universe.world.add_component(CameraXRComponent::on());
    let _ = universe.attach(xr_input, xr_head);
    let _ = universe.attach(xr_input, xr_gamepad);
    let _ = universe.attach(xr_head, xr_camera);
    universe.add(xr_input);

    // Add an OpenXR component so OpenXRSystem initializes and starts polling events.
    let xr_root = universe
        .world
        .add_component(engine::ecs::component::XrComponent::on());
    universe.add(xr_root);

    // Process init-time registrations (Text expands into glyph subtrees here).
    universe.systems.process_commands(
        &mut universe.world,
        &mut universe.visuals,
        &mut universe.render_assets,
        &mut universe.command_queue,
    );

    engine::Windowing::run_app(universe).expect("Windowing failed");
}

examples/vtuber-joints-example.rs (line 64)

fn main() {
    mittens_engine::example_support::ensure_model_assets();
    utils::logger::init();

    let world = engine::ecs::World::default();
    let mut universe = engine::Universe::new(world);

    // Slow the global beat clock so beat-based animations run half as fast.
    let clock = universe
        .world
        .add_component(ClockComponent::new().with_bpm(60.0));
    universe.add(clock);

    // Light pink background.
    let background = universe
        .world
        .add_component(BackgroundColorComponent::new());
    let background_c = universe
        .world
        .add_component(ColorComponent::rgba(1.0, 0.82, 0.90, 1.0));
    let _ = universe.world.add_child(background, background_c);
    universe.add(background);

    // Small ambient so shadowed areas aren't pure black.
    let ambient = universe
        .world
        .add_component(AmbientLightComponent::rgb(0.10, 0.10, 0.12));
    universe.add(ambient);

    // --- Camera rig (WASD + mouse) ---
    let input = universe
        .world
        .add_component(InputComponent::new().with_speed(1.5));
    let input_mode = universe.world.add_component(
        InputTransformModeComponent::forward_z()
            .with_fps_rotation()
            .with_roll_axis_y(),
    );
    let _ = universe.attach(input, input_mode);

    // Start slightly pulled back looking towards the origin.
    let rig_transform = universe
        .world
        .add_component(TransformComponent::new().with_position(0.0, 0.0, 6.0));
    let _ = universe.attach(input, rig_transform);

    let camera3d = universe.world.add_component(Camera3DComponent::new());
    let _ = universe.attach(rig_transform, camera3d);

    // Pointer so gizmos can be interacted with.
    let pointer = universe.world.add_component(PointerComponent::new());
    let _ = universe.attach(camera3d, pointer);

    // Topology: I { T { C3D } } — add a small camera-attached controls hint.
    example_util::spawn_desktop_camera_controls_hint(&mut universe, rig_transform);

    universe.add(input);

    // --- lighting ---
    let sun = universe.world.add_component(
        DirectionalLightComponent::new()
            .with_intensity(1.2)
            .with_color(1.0, 0.98, 0.94),
    );
    let sun_dir = universe
        .world
        .add_component(TransformComponent::new().with_position(0.0, -0.35, 1.0));
    let _ = universe.attach(sun_dir, sun);
    universe.add(sun_dir);

    let light_transform = universe.world.add_component(
        TransformComponent::new()
            .with_position(1.0, 6.0, 3.0)
            .with_scale(0.1, 0.1, 0.1),
    );
    let light = universe.world.add_component(
        engine::ecs::component::PointLightComponent::new()
            .with_distance(120.0)
            .with_color(1.0, 1.0, 1.0),
    );
    let _ = universe.attach(light_transform, light);
    universe.add(light_transform);

    // --- VTuber model ---
    let model_uri = "assets/models/pc-rei.hoodie.glb";

    // Wrap the model subtree in an editor root so transform-only glTF nodes can be visualized
    // (and thus raycasted/selected) without affecting non-editor scenes.
    let editor_root = universe.world.add_component(EditorComponent::new());

    let model_root = universe.world.add_component(TransformComponent::new());
    let model = universe.world.add_component(GLTFComponent::new(model_uri));

    // emissive for pc-rei
    let emissive = universe.world.add_component(EmissiveComponent::on());
    let _ = universe.attach(model, emissive);

    let xr_input = universe.world.add_component(InputXRComponent::on());
    let xr_gamepad = universe
        .world
        .add_component(engine::ecs::component::InputXRGamepadComponent::new().speed(1.5));
    let xr_head = universe.world.add_component(TransformComponent::new());
    let xr_camera = universe.world.add_component(CameraXRComponent::on());
    let _ = universe.attach(xr_input, xr_head);
    let _ = universe.attach(xr_input, xr_gamepad);
    let _ = universe.attach(xr_head, xr_camera);
    let xr_pointer = universe.world.add_component(PointerComponent::new());
    let _ = universe.attach(xr_camera, xr_pointer);
    let _ = universe.attach(xr_head, editor_root);

    let _ = universe.attach(model_root, model);

    let _ = universe.attach(editor_root, model_root);

    // Initialize the editor root so GLTFComponent gets registered.
    universe.add(xr_input);
    universe.add(editor_root);

    // --- Background clouds (occluded + lit) ---
    let bg_root = universe.world.add_component(
        engine::ecs::component::BackgroundComponent::new().with_occlusion_and_lighting(),
    );
    universe.add(bg_root);
    let mut cloud_params = example_util::CloudRingParams::default();
    cloud_params.cloud_count = 8; // +3 clusters
    cloud_params.angle_jitter = 0.35;
    cloud_params.high_y_probability = 0.5;
    cloud_params.high_y_multiplier = 1.5;
    cloud_params.seed = 0x57_55_B0_01u32;
    example_util::spawn_cloud_ring(&mut universe, bg_root, cloud_params);

    // --- Simple environment ---
    let spawn_cube = |universe: &mut engine::Universe,
                      position: (f32, f32, f32),
                      scale: (f32, f32, f32),
                      color: (f32, f32, f32, f32)| {
        let transform = universe.world.add_component(
            TransformComponent::new()
                .with_position(position.0, position.1, position.2)
                .with_scale(scale.0, scale.1, scale.2),
        );
        let renderable = universe.world.add_component(RenderableComponent::cube());
        let color = universe
            .world
            .add_component(ColorComponent::rgba(color.0, color.1, color.2, color.3));

        let _ = universe.attach(transform, renderable);
        let _ = universe.attach(renderable, color);

        universe.add(transform);
    };

    // floor
    spawn_cube(
        &mut universe,
        (0.0, -0.05, 0.0),
        (10.0, 0.1, 10.0),
        (0.92, 0.92, 0.92, 1.0),
    );

    // back wall
    spawn_cube(
        &mut universe,
        (-3.0, 1.5, -5.0),
        (3.0, 3.0, 1.0),
        (0.95, 0.94, 0.96, 1.0),
    );

    // desk
    spawn_cube(
        &mut universe,
        (0.0, 0.35, 1.0),
        (1.0, 0.75, 0.5),
        (0.75, 0.70, 0.65, 1.0),
    );

    // --- Editor-side stacked cubes (inside the editor subtree for picking/gizmos) ---
    {
        let spawn_editor_cube = |universe: &mut engine::Universe,
                                 editor_root: engine::ecs::ComponentId,
                                 name: &str,
                                 position: (f32, f32, f32),
                                 scale: (f32, f32, f32),
                                 color: (f32, f32, f32, f32)| {
            let transform = universe.world.add_component_boxed_named(
                format!("{name}_t"),
                Box::new(
                    TransformComponent::new()
                        .with_position(position.0, position.1, position.2)
                        .with_scale(scale.0, scale.1, scale.2),
                ),
            );
            let renderable = universe.world.add_component_boxed_named(
                format!("{name}_r"),
                Box::new(RenderableComponent::cube()),
            );
            let color_comp = universe.world.add_component_boxed_named(
                format!("{name}_color"),
                Box::new(ColorComponent::rgba(color.0, color.1, color.2, color.3)),
            );
            let raycastable = universe.world.add_component_boxed_named(
                format!("{name}_raycastable"),
                Box::new(RaycastableComponent::enabled()),
            );

            let _ = universe.world.add_child(transform, renderable);
            let _ = universe.world.add_child(renderable, color_comp);
            let _ = universe.world.add_child(renderable, raycastable);

            // One attach into the initialized editor subtree triggers init for the new subtree.
            let _ = universe.attach(editor_root, transform);
        };

        // Place the stack beside the desk (a bit to the right).
        let stack_x = 1.35;
        let stack_z = 1.0;
        let s = 0.25;
        let half = 0.5 * s;
        let light_brown = (0.80, 0.72, 0.55, 1.0);
        let cyan = (0.20, 1.00, 1.00, 1.0);

        spawn_editor_cube(
            &mut universe,
            editor_root,
            "editor_stack_0",
            (stack_x, half, stack_z),
            (s, s, s),
            light_brown,
        );
        spawn_editor_cube(
            &mut universe,
            editor_root,
            "editor_stack_1",
            (stack_x, half + 1.0 * s, stack_z),
            (s, s, s),
            light_brown,
        );
        spawn_editor_cube(
            &mut universe,
            editor_root,
            "editor_stack_2",
            (stack_x, half + 2.0 * s, stack_z),
            (s, s, s),
            light_brown,
        );
        spawn_editor_cube(
            &mut universe,
            editor_root,
            "editor_stack_top",
            (stack_x, half + 3.0 * s, stack_z),
            (s, s, s),
            cyan,
        );
    }

    let xr_root = universe
        .world
        .add_component(engine::ecs::component::XrComponent::on());
    universe.add(xr_root);

    universe.systems.process_commands(
        &mut universe.world,
        &mut universe.visuals,
        &mut universe.render_assets,
        &mut universe.command_queue,
    );

    // Spawn the glTF subtree once up-front so joint ComponentIds exist.
    {
        let systems = &mut universe.systems;
        systems.gltf.tick_with_queue(
            &mut universe.world,
            &mut universe.visuals,
            &mut systems.skinned_mesh,
            &mut universe.command_queue,
            0.0,
        );
    }
    universe.systems.process_commands(
        &mut universe.world,
        &mut universe.visuals,
        &mut universe.render_assets,
        &mut universe.command_queue,
    );

    // Register imported meshes into RenderAssets early so we can inspect skin weights
    // (textures will still be uploaded later during normal rendering).
    universe
        .systems
        .gltf
        .flush_mesh_imports_only(&mut universe.render_assets);

    // --- Joint printout + animation binding (in the example) ---
    let all_joints = collect_joint_transforms(
        &universe.world,
        &universe.systems.skinned_mesh,
        &universe.visuals,
        model,
        model_root,
    );
    println!("[vtuber-joints-example] joints found: {}", all_joints.len());
    for (i, (node_index, joint_tx)) in all_joints.iter().enumerate() {
        println!("  joint[{i:03}] node_index={node_index} transform={joint_tx:?}");
    }

    let node_index_to_transform: HashMap<usize, engine::ecs::ComponentId> =
        all_joints.iter().copied().collect();

    // Example settings are hardcoded to keep this example simple.
    let joint_offset: usize = 0;
    let wiggle_count: usize = 16;

    let target_mesh_key = "pc-rei.hoodie:Body_(merged).baked:prim0".to_string();
    let target_joint_names: Vec<String> = vec![
        "J_Bip_L_UpperArm".to_string(),
        "J_Bip_R_UpperArm".to_string(),
    ];

    let print_transform_updates: bool = false;

    let selected_joint_transforms: Vec<(usize, engine::ecs::ComponentId)> =
        select_named_joints(&universe.world, &all_joints, &target_joint_names)
            .or_else(|| {
                select_body_prim0_influencers(
                    &universe,
                    model_root,
                    &target_mesh_key,
                    wiggle_count,
                    &node_index_to_transform,
                )
            })
            .unwrap_or_else(|| select_joint_range(&all_joints, joint_offset, wiggle_count));
    println!(
        "[vtuber-joints-example] wiggle selection: target_mesh_key='{}' offset={} count={} selected={}",
        target_mesh_key,
        joint_offset,
        wiggle_count,
        selected_joint_transforms.len()
    );

    debug_print_selected_joint_influence(
        &universe,
        &target_mesh_key,
        model_root,
        &selected_joint_transforms,
    );

    println!("[vtuber-joints-example] selected joints:");
    for (i, (node_index, joint_tx)) in selected_joint_transforms.iter().enumerate() {
        let name = universe
            .world
            .get_component_record(*joint_tx)
            .map(|n| n.name.as_str())
            .unwrap_or("<unknown>");
        println!("  sel[{i:02}] node_index={node_index} name={name} transform={joint_tx:?}");
    }

    if print_transform_updates {
        println!("[vtuber-joints-example] note: joint animation disabled");
    }

    universe.systems.process_commands(
        &mut universe.world,
        &mut universe.visuals,
        &mut universe.render_assets,
        &mut universe.command_queue,
    );

    universe.enable_repl();
    engine::Windowing::run_app(universe).expect("Windowing failed");
}

Additional examples can be found in:

• examples/collision-perimeter.rs

pub fn disabled() -> Self

pub fn with_enabled(self, enabled: bool) -> Self

Trait Implementations

impl Clone for PointerComponent

fn clone(&self) -> PointerComponent

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Component for PointerComponent

fn name(&self) -> &'static str

Short debug/type name for this component kind (e.g. “transform”, “camera”).

fn set_id(&mut self, component: ComponentId)

fn as_any(&self) -> &dyn Any

fn as_any_mut(&mut self) -> &mut dyn Any

fn init(&mut self, emit: &mut dyn SignalEmitter, component: ComponentId)

Called when component is added to the World

fn to_mms_ast(&self, _world: &World) -> ComponentExpression

Encode this component as an MMS Component Expression AST node.

fn cleanup(&mut self, _emit: &mut dyn SignalEmitter, _component: ComponentId)

Called when component is removed from the World.

fn encode(&self) -> HashMap<String, Value>

Encode component data to a HashMap for serialization.

fn decode(&mut self, _data: &HashMap<String, Value>) -> Result<(), String>

Decode component data from a HashMap after deserialization.

impl Copy for PointerComponent

impl Debug for PointerComponent

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for PointerComponent

fn default() -> Self

Returns the “default value” for a type.