From 4e81deb125524702fb1cf2d15f3d1393bdbd3e4e Mon Sep 17 00:00:00 2001
From: Tobias Haeussler <mail@tobiashaeussler.com>
Date: Tue, 8 Mar 2022 21:15:07 +0100
Subject: [PATCH 1/2] Add glTF PBR

---
 libraries/bxdf/gltf_pbr.mtlx                  | 263 ++++++++++++++++++
 .../Examples/glTFPBR/gltf_pbr_default.mtlx    |  29 ++
 2 files changed, 292 insertions(+)
 create mode 100644 libraries/bxdf/gltf_pbr.mtlx
 create mode 100644 resources/Materials/Examples/glTFPBR/gltf_pbr_default.mtlx

diff --git a/libraries/bxdf/gltf_pbr.mtlx b/libraries/bxdf/gltf_pbr.mtlx
new file mode 100644
index 0000000000..16ddf63eaf
--- /dev/null
+++ b/libraries/bxdf/gltf_pbr.mtlx
@@ -0,0 +1,263 @@
+<?xml version="1.0"?>
+<materialx version="1.38">
+  <nodedef name="ND_gltf_pbr_surfaceshader" node="gltf_pbr" nodegroup="pbr" doc="glTF PBR" version="0.0.1" isdefaultversion="true">
+    <input name="base_color" type="color3" value="0.8, 0.8, 0.8" uimin="0, 0, 0" uimax="1, 1, 1" uiname="Base Color" uifolder="Base" />
+    <input name="metallic" type="float" value="0" uimin="0" uimax="1" uiname="Metallic" uifolder="Base" />
+    <input name="roughness" type="float" value="0" uimin="0" uimax="1" uiname="Roughness" uifolder="Base" />
+    <input name="normal" type="vector3" defaultgeomprop="Nworld" uiname="Normal" uifolder="Base" />
+    <input name="occlusion" type="float" value="0" uimin="0" uimax="1" uiname="Occlusion" uifolder="Base" />
+    <input name="transmission" type="float" value="0" uimin="0" uimax="1" uiname="Transmission" uifolder="Base" />
+    <input name="specular" type="float" value="1" uimin="0" uimax="1" uiname="Specular" uifolder="Base" />
+    <input name="specular_color" type="color3" value="1, 1, 1" uimin="0, 0, 0" uisoftmax="1, 1, 1" uiname="Specular Color" uifolder="Base" />
+    <input name="ior" uniform="true" type="float" value="1.5" uimin="1" uisoftmax="3" uiname="Index of Refraction" uifolder="Base" />
+    <input name="alpha" type="float" value="0" uimin="0" uimax="1" uiname="Alpha" uifolder="Alpha" />
+    <input name="alpha_mode" uniform="true" type="integer" enum="OPAQUE, MASK, BLEND" enumvalues="0, 1, 2" value="0" uiname="Alpha Mode" uifolder="Alpha" />
+    <input name="alpha_cutoff" uniform="true" type="float" value="0.5" uimin="0" uimax="1" uiname="Alpha Cutoff" uifolder="Alpha" />
+    <input name="sheen_color" type="color3" value="0, 0, 0" uimin="0, 0, 0" uimax="1, 1, 1" uiname="Sheen Color" uifolder="Sheen" />
+    <input name="sheen_roughness" type="float" value="0" uimin="0" uimax="1" uiname="Sheen Roughness" uifolder="Sheen" />
+    <input name="clearcoat" type="float" value="0" uimin="0" uimax="1" uiname="Clearcoat" uifolder="Clearcoat" />
+    <input name="clearcoat_roughness" type="float" value="0" uimin="0" uimax="1" uiname="Clearcoat Roughness" uifolder="Clearcoat" />
+    <input name="clearcoat_normal" type="vector3" defaultgeomprop="Nworld" uiname="Clearcoat Normal" uifolder="Clearcoat" />
+    <input name="emissive" type="color3" value="0, 0, 0" uimin="0, 0, 0" uimax="1, 1, 1" uiname="Emissive" uifolder="Emission" />
+    <input name="thickness" uniform="false" type="float" uimin="0" uiname="Thickness" uifolder="Volume" />
+    <input name="attenuation_distance" uniform="true" type="float" uimin="0" uiname="Attenuation Distance" uifolder="Volume" />
+    <input name="attenuation_color" uniform="true" type="color3" value="1, 1, 1" uimin="0, 0, 0" uimax="1, 1, 1" uiname="Attenuation Color" uifolder="Volume" />
+    <output name="out" type="surfaceshader" />
+  </nodedef>
+
+  <nodegraph name="IMPL_gltf_pbr_surfaceshader" nodedef="ND_gltf_pbr_surfaceshader">
+    <!-- Volume -->
+
+    <convert name="attenuation_color_vec" type="vector3">
+      <input name="in" type="color3" interfacename="attenuation_color" />
+    </convert>
+
+    <ln name="ln_attenuation_color_vec" type="vector3">
+      <input name="in" type="vector3" nodename="attenuation_color_vec" />
+    </ln>
+
+    <divide name="ln_attenuation_color_vec_over_distance" type="vector3">
+      <input name="in1" type="vector3" nodename="ln_attenuation_color_vec" />
+      <input name="in2" type="float" interfacename="attenuation_distance" />
+    </divide>
+
+    <multiply name="attenuation_coeff" type="vector3">
+      <input name="in1" type="vector3" nodename="ln_attenuation_color_vec_over_distance" />
+      <input name="in2" type="float" value="-1" />
+    </multiply>
+
+    <anisotropic_vdf name="isotropic_volume" type="VDF">
+      <!-- No scattering yet, so absorption_coeff == attenuation_coeff -->
+      <input name="absorption" type="vector3" nodename="attenuation_coeff" />
+      <input name="scattering" type="vector3" value="0, 0, 0" />
+      <input name="anisotropy" type="float" value="0" />
+    </anisotropic_vdf>
+
+    <!-- Base layer -->
+
+    <!-- Compute F0 and F90 of dielectric component -->
+    <subtract name="one_minus_ior" type="float">
+      <input name="in1" type="float" value="1" />
+      <input name="in2" type="float" interfacename="ior" />
+    </subtract>
+
+    <add name="one_plus_ior" type="float">
+      <input name="in1" type="float" value="1" />
+      <input name="in2" type="float" interfacename="ior" />
+    </add>
+
+    <divide name="ior_div" type="float">
+      <input name="in1" type="float" nodename="one_minus_ior" />
+      <input name="in2" type="float" nodename="one_plus_ior" />
+    </divide>
+
+    <multiply name="dielectric_f0_from_ior" type="float">
+      <input name="in1" type="float" nodename="ior_div" />
+      <input name="in2" type="float" nodename="ior_div" />
+    </multiply>
+
+    <multiply name="dielectric_f0_from_ior_specular_color" type="color3">
+      <input name="in1" type="color3" interfacename="specular_color" />
+      <input name="in2" type="float" nodename="dielectric_f0_from_ior" />
+    </multiply>
+
+    <min name="clamped_dielectric_f0_from_ior_specular_color" type="color3">
+      <input name="in1" type="color3" nodename="dielectric_f0_from_ior_specular_color" />
+      <input name="in2" type="float" value="1" />
+    </min>
+
+    <multiply name="dielectric_f0" type="color3">
+      <input name="in1" type="color3" nodename="clamped_dielectric_f0_from_ior_specular_color" />
+      <input name="in2" type="float" interfacename="specular" />
+    </multiply>
+
+    <multiply name="dielectric_f90" type="color3">
+      <input name="in1" type="color3" value="1, 1, 1" />
+      <input name="in2" type="float" interfacename="specular" />
+    </multiply>
+
+    <!-- Roughness -->
+
+    <roughness_anisotropy name="roughness_uv" type="vector2">
+      <input name="roughness" type="float" interfacename="roughness" />
+    </roughness_anisotropy>
+
+    <!-- Dielectric -->
+
+    <oren_nayar_diffuse_bsdf name="diffuse_bsdf" type="BSDF">
+      <input name="color" type="color3" interfacename="base_color" />
+      <input name="normal" type="vector3" interfacename="normal" />
+    </oren_nayar_diffuse_bsdf>
+
+    <dielectric_bsdf name="transmission_bsdf" type="BSDF">
+      <input name="weight" type="float" value="1" />
+      <input name="tint" type="color3" interfacename="base_color" />
+      <input name="ior" type="float" interfacename="ior" />
+      <input name="roughness" type="vector2" nodename="roughness_uv" />
+      <input name="normal" type="vector3" interfacename="normal" />
+      <input name="scatter_mode" type="string" value="T" />
+    </dielectric_bsdf>
+
+    <generalized_schlick_bsdf name="reflection_bsdf" type="BSDF">
+      <input name="color0" type="color3" nodename="dielectric_f0" />
+      <input name="color90" type="color3" nodename="dielectric_f90" />
+      <input name="roughness" type="vector2" nodename="roughness_uv" />
+      <input name="normal" type="vector3" interfacename="normal" />
+      <input name="scatter_mode" type="string" value="R" />
+    </generalized_schlick_bsdf>
+
+    <mix name="transmission_mix" type="BSDF">
+      <input name="bg" type="BSDF" nodename="diffuse_bsdf" />
+      <input name="fg" type="BSDF" nodename="transmission_bsdf" />
+      <input name="mix" type="float" interfacename="transmission" />
+    </mix>
+
+    <layer name="dielectric_bsdf" type="BSDF">
+      <input name="top" type="BSDF" nodename="reflection_bsdf" />
+      <input name="base" type="BSDF" nodename="transmission_mix" />
+    </layer>
+
+    <!-- Metal -->
+
+    <generalized_schlick_bsdf name="metal_bsdf" type="BSDF">
+      <input name="color0" type="color3" interfacename="base_color" />
+      <input name="color90" type="color3" value="1, 1, 1" />
+      <input name="roughness" type="vector2" nodename="roughness_uv" />
+      <input name="normal" type="vector3" interfacename="normal" />
+    </generalized_schlick_bsdf>
+
+    <!-- Dielectric/metal mix -->
+
+    <mix name="base_mix" type="BSDF">
+      <input name="bg" type="BSDF" nodename="dielectric_bsdf" />
+      <input name="fg" type="BSDF" nodename="metal_bsdf" />
+      <input name="mix" type="float" interfacename="metallic" />
+    </mix>
+
+    <!-- Sheen layer -->
+
+    <!-- Compute sheen intensity = max(sheen_color.r, sheen_color.g, sheen_color.b) -->
+    <extract name="sheen_color_r" type="float">
+      <input name="in" type="color3" interfacename="sheen_color" />
+      <input name="index" type="integer" value="0" />
+    </extract>
+
+    <extract name="sheen_color_g" type="float">
+      <input name="in" type="color3" interfacename="sheen_color" />
+      <input name="index" type="integer" value="1" />
+    </extract>
+
+    <extract name="sheen_color_b" type="float">
+      <input name="in" type="color3" interfacename="sheen_color" />
+      <input name="index" type="integer" value="2" />
+    </extract>
+
+    <max name="sheen_color_max_rg" type="float">
+      <input name="in1" type="float" nodename="sheen_color_r" />
+      <input name="in2" type="float" nodename="sheen_color_g" />
+    </max>
+
+    <max name="sheen_intensity" type="float">
+      <input name="in1" type="float" nodename="sheen_color_max_rg" />
+      <input name="in2" type="float" nodename="sheen_color_b" />
+    </max>
+
+    <multiply name="sheen_roughness_sq" type="float">
+      <input name="in1" type="float" interfacename="sheen_roughness" />
+      <input name="in2" type="float" interfacename="sheen_roughness" />
+    </multiply>
+
+    <divide name="sheen_color_normalized" type="color3">
+      <input name="in1" type="color3" interfacename="sheen_color" />
+      <input name="in2" type="float" nodename="sheen_intensity" />
+    </divide>
+
+    <sheen_bsdf name="sheen_bsdf" type="BSDF">
+      <input name="weight" type="float" nodename="sheen_intensity" />
+      <input name="color" type="color3" nodename="sheen_color_normalized" />
+      <input name="roughness" type="float" nodename="sheen_roughness_sq" />
+      <input name="normal" type="vector3" interfacename="normal" />
+    </sheen_bsdf>
+
+    <layer name="sheen_layer" type="BSDF">
+      <input name="top" type="BSDF" nodename="sheen_bsdf" />
+      <input name="base" type="BSDF" nodename="base_mix" />
+    </layer>
+
+    <!-- Clearcoat -->
+
+    <roughness_anisotropy name="clearcoat_roughness_uv" type="vector2">
+      <input name="roughness" type="float" interfacename="clearcoat_roughness" />
+    </roughness_anisotropy>
+
+    <dielectric_bsdf name="clearcoat_bsdf" type="BSDF">
+      <input name="weight" type="float" interfacename="clearcoat" />
+      <input name="roughness" type="vector2" nodename="clearcoat_roughness_uv" />
+      <input name="ior" type="float" value="1.5"/>
+      <input name="normal" type="vector3" interfacename="clearcoat_normal" />
+    </dielectric_bsdf>
+
+    <layer name="clearcoat_layer" type="BSDF">
+      <input name="top" type="BSDF" nodename="clearcoat_bsdf" />
+      <input name="base" type="BSDF" nodename="sheen_layer" />
+    </layer>
+
+    <!-- Emission -->
+
+    <uniform_edf name="emission" type="EDF">
+      <input name="color" type="color3" interfacename="emissive" />
+    </uniform_edf>
+
+    <!-- Alpha -->
+
+    <ifgreatereq name="opacity_mask_cutoff" type="float">
+      <input name="value1" type="float" interfacename="alpha" />
+      <input name="value2" type="float" interfacename="alpha_cutoff" />
+      <input name="in1" type="float" value="1" />
+      <input name="in2" type="float" value="0" />
+    </ifgreatereq>
+
+    <ifequal name="opacity_mask" type="float">
+      <input name="value1" type="integer" interfacename="alpha_mode" />
+      <input name="value2" type="integer" value="1" />
+      <input name="in1" type="float" nodename="opacity_mask_cutoff" />
+      <input name="in2" type="float" interfacename="alpha" />
+    </ifequal>
+
+    <ifequal name="opacity" type="float">
+      <input name="value1" type="integer" interfacename="alpha_mode" />
+      <input name="value2" type="integer" value="0" />
+      <input name="in1" type="float" value="1" />
+      <input name="in2" type="float" nodename="opacity_mask" />
+    </ifequal>
+
+    <!-- Surface -->
+
+    <surface name="shader_constructor" type="surfaceshader">
+      <input name="bsdf" type="BSDF" nodename="clearcoat_layer" />
+      <input name="edf" type="EDF" nodename="emission" />
+      <input name="opacity" type="float" nodename="opacity" />
+    </surface>
+    <output name="out" type="surfaceshader" nodename="shader_constructor" />
+  </nodegraph>
+</materialx>
diff --git a/resources/Materials/Examples/glTFPBR/gltf_pbr_default.mtlx b/resources/Materials/Examples/glTFPBR/gltf_pbr_default.mtlx
new file mode 100644
index 0000000000..b6ed626d0e
--- /dev/null
+++ b/resources/Materials/Examples/glTFPBR/gltf_pbr_default.mtlx
@@ -0,0 +1,29 @@
+<?xml version="1.0"?>
+<materialx version="1.38" colorspace="lin_rec709">
+  <gltf_pbr name="SR_default" type="surfaceshader">
+    <input name="base_color" type="color3" value="0.8, 0.8, 0.8" />
+    <input name="metallic" type="float" value="0" />
+    <input name="roughness" type="float" value="0" />
+    <input name="normal" type="vector3" value="0, 0, 1" />
+    <input name="occlusion" type="float" value="0" />
+    <input name="transmission" type="float" value="0" />
+    <input name="specular" type="float" value="1" />
+    <input name="specular_color" type="color3" value="1, 1, 1" />
+    <input name="ior" type="float" value="1.5" />
+    <input name="alpha" type="float" value="1" />
+    <input name="alpha_mode" type="integer" value="0" />
+    <input name="alpha_cutoff" type="float" value="0.5" />
+    <input name="sheen_color" type="color3" value="0, 0, 0" />
+    <input name="sheen_roughness" type="float" value="0" />
+    <input name="clearcoat" type="float" value="0" />
+    <input name="clearcoat_roughness" type="float" value="0" />
+    <input name="clearcoat_normal" type="vector3" value="0, 0, 1" />
+    <input name="emissive" type="color3" value="0, 0, 0" />
+    <input name="thickness" type="float" value="0" />
+    <input name="attenuation_distance" type="float" value="100000" />
+    <input name="attenuation_color" type="color3" value="0, 0, 0" />
+  </gltf_pbr>
+  <surfacematerial name="Default" type="material">
+    <input name="surfaceshader" type="surfaceshader" nodename="SR_default" />
+  </surfacematerial>
+</materialx>

From ebce97d44142916a8327ae41dda1eb9a02e55073 Mon Sep 17 00:00:00 2001
From: Tobias Haeussler <mail@tobiashaeussler.com>
Date: Sun, 13 Mar 2022 10:18:07 +0100
Subject: [PATCH 2/2] Rename folder

---
 .../Materials/Examples/{glTFPBR => GltfPbr}/gltf_pbr_default.mtlx | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 rename resources/Materials/Examples/{glTFPBR => GltfPbr}/gltf_pbr_default.mtlx (100%)

diff --git a/resources/Materials/Examples/glTFPBR/gltf_pbr_default.mtlx b/resources/Materials/Examples/GltfPbr/gltf_pbr_default.mtlx
similarity index 100%
rename from resources/Materials/Examples/glTFPBR/gltf_pbr_default.mtlx
rename to resources/Materials/Examples/GltfPbr/gltf_pbr_default.mtlx