From c9342de5bd708d309cd0df1e65fe668ecbb9a16a Mon Sep 17 00:00:00 2001
From: yum <yum.food.vr@gmail.com>
Date: Tue, 20 Jan 2026 23:30:08 -0800
Subject: Fur: add depth-based ao

---
 2ner.cginc    |  4 ++--
 2ner.shader   |  1 +
 globals.cginc |  1 +
 yum_pbr.cginc | 23 +++++++++++++++++++----
 4 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/2ner.cginc b/2ner.cginc
index 736210f..0b5ee9f 100644
--- a/2ner.cginc
+++ b/2ner.cginc
@@ -225,7 +225,7 @@ v2f vert(appdata v) {
 }
 
 //ifex _Fur_Enabled==0
-[maxvertexcount(3 * 9)]
+[maxvertexcount(3 * 10)]
 void geom(triangle v2f input[3], inout TriangleStream<v2f> stream) {
 #if defined(_FUR)
 #if defined(_FUR_MASK)
@@ -431,7 +431,7 @@ float4 frag(v2f i, uint facing : SV_IsFrontFace
 
   float4x4 tangentToWorld = float4x4(
     float4(i.tangent, 0),
-    float4(cross(i.tangent, i.normal), 0),
+    float4(f.binormal, 0),
     float4(i.normal, 0),
     float4(0, 0, 0, 1)
   );
diff --git a/2ner.shader b/2ner.shader
index 987a990..357f372 100644
--- a/2ner.shader
+++ b/2ner.shader
@@ -114,6 +114,7 @@ Shader "yum_food/2ner"
         [IntRange] _Fur_Layers("Layers", Range(1, 12)) = 1
         _Fur_Heightmap("Heightmap", 2D) = "black" {}
         _Fur_Heightmap_Mip_Bias("Heightmap mip bias", Range(-4, 4)) = 0
+        _Fur_AO_Strength("Ambient occlusion strength", Range(0, 1)) = 1
 
         [HideInInspector] m_start_Fur_Mask("Mask", Float) = 0
         [ThryToggle(_FUR_MASK)]_Fur_Mask_Enabled("Enable", Float) = 0
diff --git a/globals.cginc b/globals.cginc
index cfb7f07..4bc39b4 100644
--- a/globals.cginc
+++ b/globals.cginc
@@ -149,6 +149,7 @@ int _Fur_Layers;
 texture2D _Fur_Heightmap;
 float4 _Fur_Heightmap_ST;
 float _Fur_Heightmap_Mip_Bias;
+float _Fur_AO_Strength;
 #endif
 
 #if defined(_FUR_MASK)
diff --git a/yum_pbr.cginc b/yum_pbr.cginc
index ef07553..a9e65d6 100644
--- a/yum_pbr.cginc
+++ b/yum_pbr.cginc
@@ -137,14 +137,25 @@ void applySeaFoam(v2f i, inout YumPbr pbr) {
 }
 #endif
 
-YumPbr GetYumPbr(v2f i, f2f f, float3x3 tangentToWorld) {
-  YumPbr result = (YumPbr)0;
-
+// Returns fur thickness on [0, 1], 0 = no fur, 1 = max fur.
+float FurClip(v2f i, f2f f, inout YumPbr result) {
 #if defined(_FUR)
   float fur_layer = i.vertexLight.w;
-  float fur_thickness = _Fur_Heightmap.SampleBias(trilinear_aniso4_repeat_s, i.uv01.xy * _Fur_Heightmap_ST.xy, _Fur_Heightmap_Mip_Bias).r;
+  float2 fur_uv = i.uv01.xy * _Fur_Heightmap_ST.xy;
+  float fur_thickness = _Fur_Heightmap.SampleBias(
+      trilinear_aniso4_repeat_s, fur_uv,
+      _Fur_Heightmap_Mip_Bias).r;
   clip(fur_thickness - fur_layer / _Fur_Layers);
+  return fur_thickness;
+#else
+  return 0;
 #endif
+}
+
+YumPbr GetYumPbr(v2f i, f2f f, float3x3 tangentToWorld) {
+  YumPbr result = (YumPbr)0;
+
+  float fur_thickness = FurClip(i, f, result);
 
   float2 raw_uv = i.uv01.xy;
 #if defined(_UV_DOMAIN_WARPING)
@@ -246,6 +257,10 @@ YumPbr GetYumPbr(v2f i, f2f f, float3x3 tangentToWorld) {
   result.ao = 1;
 #endif
 
+#if defined(_FUR)
+  result.ao = lerp(result.ao, 0, fur_thickness * _Fur_AO_Strength);
+#endif
+
   applyDecals(i, result.albedo, normal_tangent, result.metallic, result.smoothness, result.emission);
   const float min_roughness_perceptual = 0.045f;
   result.smoothness = min(1.0f - min_roughness_perceptual, result.smoothness);
-- 
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