Add radial hero-cutout shader for third-person camera

Reveal the player when geometry sits between the orbit camera and the
character: a screen-space circular mask in a URP/Lit clone (HeroCutoutLit)
clips occluders in front of the player, depth-gated so only geometry nearer
than the hero is cut. The cutout lives outside UnityPerMaterial (SRP batcher
intact) and is a no-op when disarmed, so occluders look identical to URP/Lit.

A runtime driver (HeroCutout.cs on Main/GameManager) feeds the player's
screen position, radius, feather and depth into global shader properties and
only arms while the third-person orbit vcam is live; it disarms in
first-person, free-cam and the pause menu. Applied to the lobby walls via a
dedicated occluder material (floor left solid). Shipped but shelved for now.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Assets/Scripts/HeroCutout.cs

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+using UnityEngine;
+using Unity.Cinemachine;
+
+/// <summary>
+/// Drives the screen-space radial "hero cutout". Every late frame it projects the local player to
+/// screen space and feeds that position + a circle radius/feather + the player's eye-space depth into
+/// two global shader properties (<c>_HeroCutoutPosRadius</c>, <c>_HeroCutoutDepthOn</c>) that the
+/// <c>Custom/HeroCutoutLit</c> shader reads to clip occluder geometry between the camera and the
+/// player - punching a soft see-through hole toward the character.
+///
+/// The effect is only armed while the third-person orbit <see cref="CinemachineCamera"/> is the live
+/// Cinemachine camera (i.e. Player Control / Paint mode). In first-person, free-cam, or while a menu
+/// is open a different vcam is live, so the cutout disarms and occluders render solid. Disarming sets
+/// the global "enabled" flag to 0, which also matches the zero-initialised default - so any scene
+/// without this driver leaves cutout materials looking exactly like URP/Lit.
+///
+/// Attach to a persistent scene object (e.g. the GameModeManager host).
+/// </summary>
+[DisallowMultipleComponent]
+public class HeroCutout : MonoBehaviour
+{
+    [Tooltip("Orbit camera input whose CinemachineCamera must be live for the cutout to arm. Empty = found automatically.")]
+    public ThirdPersonOrbitInput orbitInput;
+
+    [Tooltip("Game mode manager, used as a fallback source for the live player. Empty = found automatically.")]
+    public GameModeManager modes;
+
+    [Header("Circle")]
+    [Tooltip("Radius of the see-through circle, as a fraction of screen height (0.13 = 13% of height).")]
+    [Range(0.02f, 0.6f)] public float radius = 0.13f;
+
+    [Tooltip("Soft-edge width of the circle, as a fraction of screen height.")]
+    [Range(0f, 0.3f)] public float feather = 0.05f;
+
+    [Tooltip("Metres added to the player's depth so geometry right at the player isn't clipped away.")]
+    public float depthBias = 0.5f;
+
+    [Tooltip("Vertical offset (m) from the follow target where the circle centres (chest/head height).")]
+    public float heightOffset = 0f;
+
+    static readonly int PosRadiusId = Shader.PropertyToID("_HeroCutoutPosRadius");
+    static readonly int DepthOnId = Shader.PropertyToID("_HeroCutoutDepthOn");
+
+    private CinemachineCamera _orbitCam;
+    private CinemachineBrain _brain;
+
+    private void Awake()
+    {
+        if (!orbitInput) orbitInput = FindFirstObjectByType<ThirdPersonOrbitInput>(FindObjectsInactive.Include);
+        if (!modes) modes = FindFirstObjectByType<GameModeManager>();
+        if (orbitInput) _orbitCam = orbitInput.GetComponent<CinemachineCamera>();
+    }
+
+    private void OnDisable() => Disarm();
+
+    private void LateUpdate()
+    {
+        Camera cam = Camera.main;
+        if (!cam) { Disarm(); return; }
+
+        if (!_brain || _brain.gameObject != cam.gameObject)
+            _brain = cam.GetComponent<CinemachineBrain>();
+
+        if (!IsThirdPersonLive()) { Disarm(); return; }
+
+        Transform target = ResolveHeroTarget();
+        if (!target) { Disarm(); return; }
+
+        Vector3 heroPos = target.position + Vector3.up * heightOffset;
+        Vector3 vp = cam.WorldToViewportPoint(heroPos);
+        if (vp.z <= 0f) { Disarm(); return; } // hero is behind the camera
+
+        Shader.SetGlobalVector(PosRadiusId, new Vector4(vp.x, vp.y, radius, Mathf.Max(feather, 1e-4f)));
+        Shader.SetGlobalVector(DepthOnId, new Vector4(vp.z + depthBias, 1f, 0f, 0f));
+    }
+
+    /// <summary>True only when the orbit vcam is the live Cinemachine camera (third-person modes).</summary>
+    private bool IsThirdPersonLive()
+    {
+        if (!_orbitCam || !_brain) return false;
+        var live = _brain.ActiveVirtualCamera as CinemachineCamera;
+        return live && live == _orbitCam;
+    }
+
+    private Transform ResolveHeroTarget()
+    {
+        if (_orbitCam && _orbitCam.Follow) return _orbitCam.Follow;
+        if (modes && modes.Player) return modes.Player.transform;
+        return null;
+    }
+
+    /// <summary>Clears the "enabled" flag so cutout materials render as plain URP/Lit.</summary>
+    private void Disarm() => Shader.SetGlobalVector(DepthOnId, Vector4.zero);
+}

Assets/Scripts/HeroCutout.cs.meta

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+fileFormatVersion: 2
+guid: c7d67030b8dcdec489471b88c35dd78b