From d18967e7138bb239f0b60521b7e4768b40d95fe0 Mon Sep 17 00:00:00 2001
From: Jerry Gamache <jerry.gamache@autodesk.com>
Date: Tue, 5 Nov 2024 11:09:44 -0500
Subject: [PATCH] Consider subsurface color in dielectric albedo

---
 libraries/bxdf/translation/standard_surface_to_usd.mtlx | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/libraries/bxdf/translation/standard_surface_to_usd.mtlx b/libraries/bxdf/translation/standard_surface_to_usd.mtlx
index 51c7d5fc6e..f1009e3a4c 100644
--- a/libraries/bxdf/translation/standard_surface_to_usd.mtlx
+++ b/libraries/bxdf/translation/standard_surface_to_usd.mtlx
@@ -12,6 +12,8 @@
     <input name="coat" type="float" value="0" />
     <input name="coat_color" type="color3" value="1, 1, 1" />
     <input name="coat_roughness" type="float" value="0.1" />
+    <input name="subsurface" type="float" value="0" />
+    <input name="subsurface_color" type="color3" value="1, 1, 1" />
     <input name="emission" type="float" value="0" />
     <input name="emission_color" type="color3" value="1, 1, 1" />
     <input name="opacity" type="color3" value="1, 1, 1" />
@@ -47,13 +49,18 @@
       <input name="in1" type="color3" interfacename="base_color" />
       <input name="in2" type="float" interfacename="base" />
     </multiply>
+    <mix name="albedoOpaqueDielectric" type="color3">
+      <input name="fg" type="color3" interfacename="subsurface_color" />
+      <input name="bg" type="color3" nodename="scaledBaseColor" />
+      <input name="mix" type="float" interfacename="subsurface" />
+    </mix>
     <mix name="coatAttenuation" type="color3">
       <input name="fg" type="color3" interfacename="coat_color" />
       <input name="bg" type="color3" value="1.0, 1.0, 1.0" />
       <input name="mix" type="float" interfacename="coat" />
     </mix>
     <multiply name="diffuseColor" type="color3">
-      <input name="in1" type="color3" nodename="scaledBaseColor" />
+      <input name="in1" type="color3" nodename="albedoOpaqueDielectric" />
       <input name="in2" type="color3" nodename="coatAttenuation" />
     </multiply>
     <dot name="roughness" type="float">