# Starter Kit Script Reference Every C# script across the three Unity 6 starter kits, with what it does and the main concept it teaches. All runtime scripts are namespaced per kit (`UIToolkitStarterKit`, `InputSystemStarterKit`, `EnemyAIStarterKit`); editor scripts live in `Editor/` subfolders and never ship in builds. --- ## UI Toolkit Starter Kit *(Plus two non-script assets the scripts drive: `HUD.uxml` — the UI layout — and `StarterKit.uss` — all styling, button states, and transitions.)* | Script | Path | What it does | |---|---|---| | **HealthScoreSystem** | `Scripts/` | The *model*: holds health and score, clamps values, and fires C# events (`HealthChanged`, `ScoreChanged`) when they change. Contains zero UI code — teaches model/view separation. | | **HUDController** | `Scripts/` | The *view*: grabs the UIDocument's root, queries elements by name (`root.Q<T>()`), forwards button clicks and slider changes to the model, and repaints labels/bars when the model's events fire. Also drives USS classes from code (low-health red bar, score "pop"). | | **StarterKitSetup** *(editor)* | `Scripts/Editor/` | Adds **Tools → UI Toolkit Starter Kit** menu items. Creates the Panel Settings asset and runtime theme (.tss) if missing, then builds a ready-to-play HUD GameObject (UIDocument + both scripts, wired) in the current scene. | --- ## Input System Starter Kit *(Plus `StarterKitControls.inputactions` — the shared actions asset with `Player2D`, `Player3D`, and `Puzzle` maps, bound for keyboard/mouse and gamepad. Every script below reads from it.)* | Script | Path | What it does | |---|---|---| | **PlayerController2D** | `Scripts/Platformer2D/` | Side-scroller movement on a Rigidbody2D: polls `Move`, uses `Jump`'s `performed`/`canceled` events for jump buffering and variable jump height, plus coyote time and a ground BoxCast. Teaches the poll-values / subscribe-to-moments pattern. | | **FirstPersonController** | `Scripts/FirstPerson/` | FPS move/look/jump/sprint on a CharacterController. Everything is polled (`ReadValue`, `WasPressedThisFrame`) as the counterpart to the 2D script's events. Contains the kit's one device branch: mouse-delta vs stick sensitivity via `activeControl`. | | **WeaponSwitcher** | `Scripts/FirstPerson/` | Weapon slots and firing: scroll-wheel up/down and shoulder buttons cycle weapons, 1/2/3 jump to slots (subscribed in a loop with a captured-index lambda), and `Fire` hitscan-raycasts from screen center, painting what it hits. | | **DragAndDropController** | `Scripts/Puzzle/` | Pointer drag-and-drop: one `Point` action fed by mouse, pen, *and* touch; `Click.started`/`canceled` as press/release; screen→world conversion; snap-to-nearest-free-slot on release; Esc/B cancels the drag. | | **SelectionCycler** | `Scripts/Puzzle/` | Keyboard/gamepad selection cycling (Tab/E/Q, shoulder buttons) with scale+opacity highlight — the no-pointer accessibility path through the puzzle demo. | | **Draggable** | `Scripts/Puzzle/` | Tiny marker component: makes an object grabbable, remembers its home position and which slot it occupies, and can `ReturnHome()`. | | **SnapSlot** | `Scripts/Puzzle/` | Tiny drop-target component: a snap radius and an occupancy flag, with a gizmo showing the radius. | | **InputKitSetup** *(editor)* | `Scripts/Editor/` | Adds **Tools → Input System Starter Kit** menu items that build all three playable demo rigs from primitives — generating a white square sprite and pipeline-agnostic materials on demand. If the Input System package is missing, a fallback menu item shows install help instead. | --- ## Enemy AI Starter Kit | Script | Path | What it does | |---|---|---| | **TargetSensor** | `Scripts/Enemy3D/` | Reusable detector answering "can I detect the target?": range check → field-of-view cone → line-of-sight linecast, cheapest first, each toggleable. The 3D enemy carries two — long-range vision (12u/110°/LOS) and short-range attack reach (2.2u/360°). Draws its ranges as gizmos. | | **EnemyAI3D** | `Scripts/Enemy3D/` | The 3D brain: a Patrol → Chase → Attack finite state machine on a NavMeshAgent. Patrols waypoints with idle pauses, chases via `SetDestination`, attacks on a cooldown while facing the player, and returns to the nearest patrol point after a 3-second lose-sight timer. | | **GridPathfinder2D** | `Scripts/TopDown2D/` | A complete, readable A* implementation (~150 lines). Bakes a walkability grid from *static* colliders (anything without a Rigidbody2D), then `FindPath()` returns a world-space route with octile heuristic, no corner cutting, and nearest-walkable goal fallback. One instance serves all enemies. | | **EnemyAI2D** | `Scripts/TopDown2D/` | The top-down brain: deliberately the *same* FSM as EnemyAI3D, but the movement layer follows A* paths node-by-node and detection is radius + wall-blocking linecast. Repaths on a 0.5 s timer while chasing. Side-by-side comparison with the 3D script is the kit's core design lesson. | | **PlatformerEnemy2D** | `Scripts/Platformer2D/` | The "smarter than back-and-forth" patroller: wall and ledge raycast *feelers* (patrols any platform unedited), forward-only vision with height band and LOS, an alert telegraph pause before charging, edge-aware chasing that never walks off cliffs, and a give-up leash. States: Patrol → Alert → Chase → Attack. | | **DamageFlash** | `Scripts/Common/` | Feedback helper: flashes a Renderer or SpriteRenderer red for a moment. Enemies call it on the player when they attack — the marked stand-in for a real damage system. | | **DemoPlayer3D** | `Scripts/Common/` | Minimal WASD CharacterController mover so the enemy has prey. Reads the keyboard directly under either input backend — deliberately not an input lesson, just a zero-dependency demo driver. | | **DemoPlayer2D** | `Scripts/Common/` | Same idea in 2D, with two inspector-selectable modes: TopDown (4-way, no gravity) and Platformer (run + jump + gravity). | | **FollowCamera** | `Scripts/Common/` | Smoothly follows a target from a fixed offset, always looking at it — lets you watch the 3D chase unfold. | | **EnemyKitSetup** *(editor)* | `Scripts/Editor/` | Adds **Tools → Enemy AI Starter Kit** menu items building all three demo arenas from primitives. Bakes the NavMesh automatically (via reflection so the kit compiles without the AI Navigation package), baking the level *before* spawning characters, and persists the baked data as an asset. | --- ## Cross-kit patterns (what repeats on purpose) - **Editor rig builders** — every kit's `...Setup.cs` makes the fiddly setup one menu click, builds demos from primitives (zero art files), and doubles as an editor-scripting worked example (`SerializedObject` for private fields, asset generation, menu items). - **`#if ENABLE_INPUT_SYSTEM` guards** — Input System-dependent scripts compile out cleanly when the package is absent, so imports never explode with errors. - **Model/view & sense/decide/act separation** — HealthScoreSystem↔HUDController and TargetSensor↔EnemyAI↔movement are the same architectural lesson at two scales. - **Gizmos everywhere** — sensors, feelers, patrol routes, paths, and snap radii all draw themselves when selected; invisible-state bugs become visible. - **Debug tints and `Debug.Log` hooks** — state changes are visible without art, and every "deal damage here" moment is a clearly marked hook for real systems.