Fur: add depth-based ao

1 files changed, 19 insertions, 4 deletions

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);