From 17fd1b7e9ff667a1d79be059396e28dc0be6ffc3 Mon Sep 17 00:00:00 2001
From: Bernard Kwok <kwokcb@gmail.com>
Date: Mon, 29 Jan 2024 14:00:58 -0500
Subject: [PATCH] Add an upstream graph to compute warm / cool colours based on
 math in Gooch98 paper. Any warm or cool colour computation could be
 connected.

---
 .../TestSuite/nprlib/gooch_shade.mtlx         | 55 ++++++++++++++++++-
 1 file changed, 52 insertions(+), 3 deletions(-)

diff --git a/resources/Materials/TestSuite/nprlib/gooch_shade.mtlx b/resources/Materials/TestSuite/nprlib/gooch_shade.mtlx
index 05220a22ed..62e642e773 100644
--- a/resources/Materials/TestSuite/nprlib/gooch_shade.mtlx
+++ b/resources/Materials/TestSuite/nprlib/gooch_shade.mtlx
@@ -1,6 +1,8 @@
 <?xml version="1.0"?>
 <materialx version="1.38">
-  <gooch_shade name="default_gooch" type="color3" />
+  <gooch_shade name="default_gooch" type="color3">
+    <input name="shininess" type="float" value="32" />
+  </gooch_shade>
   <surface_unlit name="unlit_surface" type="surfaceshader">
     <input name="emission_color" type="color3" nodename="default_gooch" />
     <input name="opacity" type="float" value="1.0" />
@@ -12,9 +14,9 @@
   <gooch_shade name="red_blue_gooch" type="color3">
     <input name="warm_color" type="color3" value="1, 0, 0" />
     <input name="cool_color" type="color3" value="0, 2.38419e-07, 1" />
-    <input name="specular_intensity" type="float" value="0.5" />
+    <input name="specular_intensity" type="float" value="0.999" />
     <input name="shininess" type="float" value="32" />
-    <input name="light_direction" type="vector3" value="-1, -0.5, -0.5" />
+    <input name="light_direction" type="vector3" value="1, -0.5, -0.5" />
   </gooch_shade>
   <surface_unlit name="unlit_surface2" type="surfaceshader">
     <input name="emission_color" type="color3" nodename="red_blue_gooch" />
@@ -24,4 +26,51 @@
     <input name="surfaceshader" type="surfaceshader" nodename="unlit_surface2" />
     <input name="displacementshader" type="displacementshader" value="" />
   </surfacematerial>
+  <nodegraph name="NG_gooch_warm_cool" type="color3">
+    <input name="diffuse_color" type="color3" value="1, 1, 1" doc="Diffuse Color" uiname="Diffuse Color" />
+    <input name="blue_tone" type="float" value="0.4" uimin="0" uimax="1" doc="Blue tone" uiname="Blue Tone" />
+    <input name="yellow_tone" type="float" value="0.4" uimin="0" uimax="1" doc="Yellow Tone" uiname="Yellow Tone" />
+    <input name="diffuse_blue_strength" type="float" value="0.2" uimin="0" uimax="1" doc="Diffuse Blue Strength" uiname="Diffuse Blue Strength" />
+    <input name="diffuse_yellow_strength" type="float" value="0.6" doc="Luminance Shift" uiname="Diffuse Yellow Strength" />
+    <swizzle name="swizzle_float_color3" type="color3">
+      <input name="in" type="float" interfacename="blue_tone" />
+      <input name="channels" type="string" value="00b" />
+    </swizzle>
+    <swizzle name="swizzle_float_color4" type="color3">
+      <input name="in" type="float" interfacename="yellow_tone" />
+      <input name="channels" type="string" value="rg0" />
+    </swizzle>
+    <add name="k_cool" type="color3">
+      <input name="in1" type="color3" nodename="multiply_color3FA3" />
+      <input name="in2" type="color3" nodename="swizzle_float_color3" />
+    </add>
+    <add name="k_warm" type="color3">
+      <input name="in2" type="color3" nodename="swizzle_float_color4" />
+      <input name="in1" type="color3" nodename="multiply_color3FA2" />
+    </add>
+    <multiply name="multiply_color3FA2" type="color3">
+      <input name="in2" type="float" interfacename="diffuse_yellow_strength" />
+      <input name="in1" type="color3" interfacename="diffuse_color" />
+    </multiply>
+    <multiply name="multiply_color3FA3" type="color3">
+      <input name="in1" type="color3" interfacename="diffuse_color" />
+      <input name="in2" type="float" interfacename="diffuse_blue_strength" />
+    </multiply>
+    <output name="out_cool" type="color3" nodename="k_cool" />
+    <output name="out_warm" type="color3" nodename="k_warm" />
+  </nodegraph>
+  <gooch_shade name="gooch_shad3e" type="color3">
+    <input name="cool_color" type="color3" output="out_cool" nodegraph="NG_gooch_warm_cool" />
+    <input name="warm_color" type="color3" output="out_warm" nodegraph="NG_gooch_warm_cool" />
+    <input name="light_direction" type="vector3" value="1, -0.5, -0.5" />
+    <input name="shininess" type="float" value="32" />
+  </gooch_shade>
+  <surface_unlit name="unlit_surface3" type="surfaceshader">
+    <input name="emission_color" type="color3" nodename="gooch_shad3e" />
+    <input name="opacity" type="float" value="1.0" />
+  </surface_unlit>
+  <surfacematerial name="surfacematerial3" type="material">
+    <input name="surfaceshader" type="surfaceshader" nodename="unlit_surface3" />
+    <input name="displacementshader" type="displacementshader" value="" />
+  </surfacematerial>
 </materialx>