FurShell: scale-aware length/curvature + X-ray glow mirror

The fur is drawn from a CPU-baked unit-scale mesh whose instance matrix
carries the avatar's world scale, so the extrusion scaled fully 1:1 with
the player (hider 0.5 / hunter 1.5). That read as too-short fur on the
small hider and too-long on the big hunter, and the curvature droop was
sized off the raw unity_ObjectToWorld which doesn't carry the per-instance
scale in the RenderMeshInstanced path.

- FurShellRenderer pushes the avatar's lossyScale (_FurObjScale) plus a new
  Fur Scale Influence (0..1, default 0.5) that blends the fur SIZE between
  fully proportional (1) and a constant world length (0). The shader
  pre-divides the object-space displacement so the net world length follows
  effScale; curl droop and wind use the same effScale, keeping the curl
  SHAPE invariant across avatar sizes and influence settings.
- The body's see-through X-ray reveal (forward half) is mirrored onto the
  visible fur so strands glow WITH the reveal instead of hiding it under
  opaque fur. FurShellRenderer pulls the live colour/pulse/flash from the
  sibling MeshPainter (new getters), in phase with the body. A new X-Ray
  Fur Strength (default 0.2) tames the per-shell accumulation, since the
  body writes the glow once (opaque) but the fur stacks N transparent
  shells that each composite it.

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

Assets/Scripts/Components/FurShellRenderer.cs

@@ -41,6 +41,11 @@ namespace Chameleon.Components
         // direction so the flat shell slices merge into continuous strands at the rim instead of squished
         // dots. 0 = off (footprint stays circular everywhere).
         [SerializeField, Range(0f, 5f)] float _silhouetteStretch = 2f;
+        // How much the avatar's world scale drives the fur SIZE. 1 = fully proportional (small avatar => small
+        // fur, like the body). 0 = constant world size (same absolute fur length at any avatar scale). Fully
+        // proportional fur reads as too short on the small hider and too long on the big hunter, so dial this
+        // down to keep the fur closer to a fixed world length; the curl keeps its shape at any setting.
+        [SerializeField, Range(0f, 1f)] float _furScaleInfluence = 0.5f;
 
         [Header("Shading")]
         // Optional albedo (strand-colour) override for the standalone prototype; a sibling MeshPainter's
@@ -79,6 +84,14 @@ namespace Chameleon.Components
         // Sway direction in the object's XZ plane; normalized in the shader.
         [SerializeField] Vector2 _windDirection = new Vector2(1f, 0f);
 
+        [Header("X-Ray Reveal")]
+        // The sibling MeshPainter's body see-through reveal is mirrored onto the fur so the strands glow WITH
+        // the reveal instead of hiding it under opaque fur (colour/pulse are pulled from the painter, in phase
+        // with the body). The fur draws up to _shellCount stacked TRANSPARENT shells, so that additive glow
+        // composites once per overlapping layer and blows out; this scales the per-shell glow down to tame the
+        // stacking so the total reads at roughly the body's intensity. Lower = subtler.
+        [SerializeField, Range(0f, 1f)] float _xrayFurStrength = 0.2f;
+
         [Header("Rendering")]
         [SerializeField] ShadowCastingMode _shadowMode = ShadowCastingMode.Off;
         [SerializeField] bool _receiveShadows = true;
@@ -110,6 +123,13 @@ namespace Chameleon.Components
         static readonly int WindSpeedId = Shader.PropertyToID("_WindSpeed");
         static readonly int WindFrequencyId = Shader.PropertyToID("_WindFrequency");
         static readonly int WindDirectionId = Shader.PropertyToID("_WindDirection");
+        static readonly int FurObjScaleId = Shader.PropertyToID("_FurObjScale");
+        static readonly int FurScaleInfluenceId = Shader.PropertyToID("_FurScaleInfluence");
+        static readonly int XRayColorId = Shader.PropertyToID("_XRayColor");
+        static readonly int XRayPulseSpeedId = Shader.PropertyToID("_XRayPulseSpeed");
+        static readonly int XRayPulseStrengthId = Shader.PropertyToID("_XRayPulseStrength");
+        static readonly int XRayPulseShapeId = Shader.PropertyToID("_XRayPulseShape");
+        static readonly int XRayFurStrengthId = Shader.PropertyToID("_XRayFurStrength");
 
         MeshFilter _meshFilter;
         SkinnedColliderBaker _baker;
@@ -243,6 +263,31 @@ namespace Chameleon.Components
             _mpb.SetFloat(WindSpeedId, _windSpeed);
             _mpb.SetFloat(WindFrequencyId, _windFrequency);
             _mpb.SetVector(WindDirectionId, new Vector4(_windDirection.x, _windDirection.y, 0f, 0f));
+
+            // Avatar world scale (uniform via PlayerScaler) = the scale baked into the instance matrix used
+            // for the shell extrusion, so the shader can scale the curvature droop in lockstep and keep the
+            // curl proportional at any player size (hider 0.5 / hunter 1.5). Read from lossyScale because
+            // the raw object matrix does NOT carry the per-instance scale in the RenderMeshInstanced path.
+            _mpb.SetFloat(FurObjScaleId, transform.lossyScale.y);
+            // Blend the fur size between fully proportional to the avatar (1) and a constant world size (0):
+            // the shader pre-divides the object-space displacement so the net world length follows this.
+            _mpb.SetFloat(FurScaleInfluenceId, _furScaleInfluence);
+
+            // Mirror the sibling painter's live body X-ray reveal onto the fur so the strands glow WITH the
+            // reveal (see-through camo) instead of hiding it under opaque fur. Same colour/pulse/flash the
+            // body uses => in phase. ToRenderColor matches the raw MPB upload to Material.SetColor's gamma
+            // handling (same convention as the fur tint above). Off (alpha 0) when no painter or not revealed
+            // => the shader's additive term is zero, so the fur is unchanged.
+            if (_painter)
+            {
+                _mpb.SetColor(XRayColorId, ToRenderColor(_painter.CurrentXRayColor));
+                _mpb.SetFloat(XRayPulseSpeedId, _painter.XRayPulseSpeed);
+                _mpb.SetFloat(XRayPulseStrengthId, _painter.XRayPulseStrength);
+                _mpb.SetFloat(XRayPulseShapeId, _painter.XRayPulseShape);
+                // Per-shell glow scale: the body writes the reveal once (opaque) but the fur stacks many
+                // transparent shells that each composite it, so scale it down to keep the total near the body.
+                _mpb.SetFloat(XRayFurStrengthId, _xrayFurStrength);
+            }
         }
 
         // MaterialPropertyBlock.SetColor uploads raw values (unlike Material.SetColor it does no gamma

Assets/Scripts/Components/MeshPainter/MeshPainter.cs

@@ -139,6 +139,31 @@ public partial class MeshPainter : MonoBehaviour
         if (flash != _xrayFlash) { _xrayFlash = flash; ApplyXRayFlashState(); }
     }
 
+    /// <summary>The live see-through X-ray glow currently on the body material (rgb = glow colour incl. any
+    /// hit-flash boost, a = eased fade master), for a sibling <see cref="Chameleon.Components.FurShellRenderer"/>
+    /// to mirror onto the fur so the strands glow WITH the reveal instead of hiding it. Fully off
+    /// (alpha 0) until a reveal fades in, or before the material instance is set up.</summary>
+    public Color CurrentXRayColor =>
+        _materialInstance && _materialInstance.HasProperty(XRayColorId)
+            ? _materialInstance.GetColor(XRayColorId)
+            : new Color(0f, 0f, 0f, 0f);
+
+    /// <summary>Authored X-ray breathing pulse speed (0 = steady), mirrored onto the fur so its glow breathes
+    /// in phase with the body's forward/overlay halves.</summary>
+    public float XRayPulseSpeed =>
+        _materialInstance && _materialInstance.HasProperty(XRayPulseSpeedId)
+            ? _materialInstance.GetFloat(XRayPulseSpeedId) : 0f;
+
+    /// <summary>Live X-ray pulse strength (the hit flash drops this to 0 for a steady pop), mirrored onto the fur.</summary>
+    public float XRayPulseStrength =>
+        _materialInstance && _materialInstance.HasProperty(XRayPulseStrengthId)
+            ? _materialInstance.GetFloat(XRayPulseStrengthId) : 0f;
+
+    /// <summary>Authored X-ray pulse shape, mirrored onto the fur so its breathing matches the body.</summary>
+    public float XRayPulseShape =>
+        _materialInstance && _materialInstance.HasProperty(XRayPulseShapeId)
+            ? _materialInstance.GetFloat(XRayPulseShapeId) : 1f;
+
     [Tooltip("Seconds for the see-through X-ray reveal glow to fade fully in or out when toggled (0 = instant snap).")]
     [Min(0f)]
     [SerializeField] private float xrayFadeDuration = 0.3f;
@@ -431,7 +456,9 @@ public partial class MeshPainter : MonoBehaviour
     private static readonly int HalfLambertBrightnessId = Shader.PropertyToID("_HalfLambertBrightness");
     private static readonly int SpecularDampenId = Shader.PropertyToID("_SpecularDampen");
     private static readonly int XRayColorId = Shader.PropertyToID("_XRayColor");
+    private static readonly int XRayPulseSpeedId = Shader.PropertyToID("_XRayPulseSpeed");
     private static readonly int XRayPulseStrengthId = Shader.PropertyToID("_XRayPulseStrength");
+    private static readonly int XRayPulseShapeId = Shader.PropertyToID("_XRayPulseShape");
     private static readonly int BrushColorId = Shader.PropertyToID("_BrushColor");
     private static readonly int ColorWriteMaskId = Shader.PropertyToID("_ColorWriteMask");
     private static readonly int BrushCenterId = Shader.PropertyToID("_BrushCenter");