Fur als 4. Paint-Map + Ziel-Opacity-Blend

Fur wird die vierte kanonische Paint-Map (RGB=Farbe, A=Länge). Integration
über Seed (kahl), GPU/CPU-Paint, Undo, Netzwerk-Sync, Persistence (fur.png,
v6) und Live-RT-Hook im FurShellRenderer. HUD-Binding (Toggle/Picker/Alpha)
aktiviert. Fur-Alpha lerpt jetzt zu einer Ziel-Opacity (Slider_FurOpacity)
statt additiv Richtung 1 zu akkumulieren (zwei Brush-Passes: Fade + Deposit).

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

Assets/Scripts/Components/FurShellRenderer.cs

@@ -53,7 +53,9 @@ namespace Chameleon.Components
 
         [Header("Fur Map")]
         // RGBA fur map: RGB = per-texel strand colour, A = fur length (0 = bald, 1 = full length). Leave
-        // null on the standalone prototype - the shader's white default is uniform full-length fur.
+        // null on the standalone prototype - the shader's white default is uniform full-length fur. A
+        // sibling MeshPainter's live fur RT overrides this when present, so a painted avatar grows fur in
+        // real time (see PushProperties).
         [SerializeField] Texture _furMap;
         // Fur is fully cut where the map's alpha is at/below this - keeps stray dilation fuzz from growing
         // hair. 0 keeps the exact "alpha 0 = no fur" contract.
@@ -101,6 +103,9 @@ namespace Chameleon.Components
 
         MeshFilter _meshFilter;
         SkinnedColliderBaker _baker;
+        // Optional sibling paint source: when present, its live fur RT (RGB = colour, A = length) overrides
+        // the serialized _furMap so painting the fur map drives the shells in real time.
+        MeshPainter _painter;
         Matrix4x4[] _instances;
         MaterialPropertyBlock _mpb;
 
@@ -110,6 +115,7 @@ namespace Chameleon.Components
             // On a skinned avatar the fur borrows this component's per-frame baked pose instead of a
             // static MeshFilter mesh (see ResolveMesh).
             _baker = GetComponent<SkinnedColliderBaker>();
+            _painter = GetComponent<MeshPainter>();
             _mpb = new MaterialPropertyBlock();
             // RenderMeshInstanced requires the material's GPU-instancing flag; guarantee it here so any
             // assigned FurShell material just works without the manual inspector checkbox.
@@ -206,7 +212,9 @@ namespace Chameleon.Components
             _mpb.SetFloat(SilhouetteStretchId, _silhouetteStretch);
 
             if (_baseMap) _mpb.SetTexture(BaseMapId, _baseMap);
-            if (_furMap) _mpb.SetTexture(FurMapId, _furMap);
+            // Prefer the sibling painter's live fur RT (painted colour + length) over the serialized map.
+            Texture furTex = _painter && _painter.FurMapTexture ? _painter.FurMapTexture : _furMap;
+            if (furTex) _mpb.SetTexture(FurMapId, furTex);
             _mpb.SetColor(BaseColorId, ToRenderColor(_rootColor));
             _mpb.SetColor(TipColorId, ToRenderColor(_tipColor));
             _mpb.SetFloat(RootAOId, _rootAO);