From a4397df0aa231bc42843b3fe53e07c7cc7083ebc Mon Sep 17 00:00:00 2001
From: Jamie Portsmouth <jamie.portsmouth@autodesk.com>
Date: Sat, 16 Sep 2023 23:21:02 +0100
Subject: [PATCH] Fix attenuation of coated emission in MaterialX (#102)

---
 reference/open_pbr_surface.mtlx | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/reference/open_pbr_surface.mtlx b/reference/open_pbr_surface.mtlx
index b4e343d2..75088533 100644
--- a/reference/open_pbr_surface.mtlx
+++ b/reference/open_pbr_surface.mtlx
@@ -378,9 +378,13 @@
       <input name="in1" type="EDF" nodename="emission_edf" />
       <input name="in2" type="color3" interfacename="coat_color" />
     </multiply>
+    <subtract name="one_minus_coat_F0" type="float">
+      <input name="in1" type="float" value="1.0" />
+      <input name="in2" type="float" nodename="coat_ior_to_F0" />
+    </subtract>
     <generalized_schlick_edf name="coat_emission_edf" type="EDF">
-      <input name="color0" type="color3" value="1.0, 1.0, 1.0" />
-      <input name="color90" type="color3" nodename="coat_ior_to_F0" channels="rrr" />
+      <input name="color0" type="color3" nodename="one_minus_coat_F0" channels="rrr" />
+      <input name="color90" type="color3" value="0.0, 0.0, 0.0" />
       <input name="exponent" type="float" value="5.0" />
       <input name="base" type="EDF" nodename="coat_tinted_emission_edf" />
     </generalized_schlick_edf>