Initial nprlib with viewdirection node (AcademySoftwareFoundation#1631)

This changelist introduces an NPR (non-photorealistic rendering) data library to MaterialX, initially consisting of a single `viewdirection` node. The NPR data library is designed for the portable expression of artistic, non-physically-based materials, with common examples being cartoon shading, architectural diagrams, and edge highlighting. In future versions of MaterialX, we expect this data library to be extended with additional primitives and artist-facing graphs as they are requested by the graphics community and approved by the MaterialX TSC. For shader generation, MaterialX initially supports the NPR data library in GLSL, ESSL, MSL, and OSL, with MDL being omitted for now, based on intentional restrictions in its design philosophy.
kwokcb · Jan 4, 2024 · 39d6d5b · 39d6d5b
1 parent 473d563
commit 39d6d5b
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Showing 18 changed files with 338 additions and 69 deletions.
diff --git a/libraries/nprlib/genglsl/nprlib_genglsl_impl.mtlx b/libraries/nprlib/genglsl/nprlib_genglsl_impl.mtlx
@@ -0,0 +1,17 @@
+<?xml version="1.0"?>
+<materialx version="1.38">
+  <!--
+    Copyright Contributors to the MaterialX Project
+    SPDX-License-Identifier: Apache-2.0
+
+    Declarations for GLSL implementations of standard nodes included in the MaterialX specification.
+  -->
+
+  <!-- ======================================================================== -->
+  <!-- View-dependent nodes                                                     -->
+  <!-- ======================================================================== -->
+
+  <!-- <viewdirection> -->
+  <implementation name="IM_viewdirection_vector3_genglsl" nodedef="ND_viewdirection_vector3" target="genglsl"/>
+
+</materialx>
diff --git a/libraries/nprlib/genmdl/nprlib_genmdl_impl.mtlx b/libraries/nprlib/genmdl/nprlib_genmdl_impl.mtlx
@@ -0,0 +1,17 @@
+<?xml version="1.0"?>
+<materialx version="1.38">
+  <!--
+    Copyright Contributors to the MaterialX Project
+    SPDX-License-Identifier: Apache-2.0
+
+    Declarations for MDL implementations of standard nodes included in the MaterialX specification.
+  -->
+
+  <!-- ======================================================================== -->
+  <!-- View-dependent nodes                                                     -->
+  <!-- ======================================================================== -->
+
+  <!-- <viewdirection> -->
+  <implementation name="IM_viewdirection_vector3_genmdl" nodedef="ND_viewdirection_vector3" sourcecode="mx::stdlib::mx_viewdirection_vector3()" target="genmdl"/>
+
+</materialx>
diff --git a/libraries/nprlib/genmsl/nprlib_genmsl_impl.mtlx b/libraries/nprlib/genmsl/nprlib_genmsl_impl.mtlx
@@ -0,0 +1,17 @@
+<?xml version="1.0"?>
+<materialx version="1.38">
+  <!--
+    Copyright Contributors to the MaterialX Project
+    SPDX-License-Identifier: Apache-2.0
+
+    Declarations for MSL implementations of standard nodes included in the MaterialX specification.
+  -->
+
+  <!-- ======================================================================== -->
+  <!-- View-dependent nodes                                                     -->
+  <!-- ======================================================================== -->
+
+  <!-- <viewdirection> -->
+  <implementation name="IM_viewdirection_vector3_genmsl" nodedef="ND_viewdirection_vector3" target="genmsl"/>
+
+</materialx>
diff --git a/libraries/nprlib/genosl/nprlib_genosl_impl.mtlx b/libraries/nprlib/genosl/nprlib_genosl_impl.mtlx
@@ -0,0 +1,17 @@
+<?xml version="1.0"?>
+<materialx version="1.38">
+  <!--
+    Copyright Contributors to the MaterialX Project
+    SPDX-License-Identifier: Apache-2.0
+
+    Declarations for OSL implementations of standard nodes included in the MaterialX specification.
+  -->
+
+  <!-- ======================================================================== -->
+  <!-- View-dependent nodes                                                     -->
+  <!-- ======================================================================== -->
+
+  <!-- <viewdirection> -->
+  <implementation name="IM_viewdirection_vector3_genosl" nodedef="ND_viewdirection_vector3" sourcecode="transform({{space}}, I)" target="genosl" />
+
+</materialx>
diff --git a/libraries/nprlib/nprlib_defs.mtlx b/libraries/nprlib/nprlib_defs.mtlx
@@ -0,0 +1,23 @@
+<?xml version="1.0"?>
+<materialx version="1.38">
+  <!--
+    Copyright Contributors to the MaterialX Project
+    SPDX-License-Identifier: Apache-2.0
+
+    Declarations of standard data types and nodes included in the MaterialX specification.
+  -->
+
+  <!-- ======================================================================== -->
+  <!-- View-dependent nodes                                                     -->
+  <!-- ======================================================================== -->
+
+  <!--
+    Node: <viewdirection>
+    The current scene view direction, as defined by the shading environment.
+  -->
+  <nodedef name="ND_viewdirection_vector3" node="viewdirection" nodegroup="npr">
+    <input name="space" type="string" value="world" enum="model,object,world" uniform="true" />
+    <output name="out" type="vector3" default="0.0, 0.0, 1.0" />
+  </nodedef>
+
+</materialx>
diff --git a/resources/Lights/envmap_shader.mtlx → resources/Lights/environment_map.mtlx b/resources/Lights/envmap_shader.mtlx → resources/Lights/environment_map.mtlx
@@ -1,17 +1,10 @@
 <?xml version="1.0"?>
-<materialx version="1.38">
+<materialx version="1.38" colorspace="lin_rec709">
 
-  <!-- Custom node: <viewdir>                     -->
-  <!-- Required by environment shader graph below -->
-  <nodedef name="ND_viewdir_vector3" node="viewdir">
-    <output name="out" type="vector3" default="0.0, 0.0, 1.0" />
-  </nodedef>
-  <implementation name="IM_viewdir_vector3_genglsl" nodedef="ND_viewdir_vector3" target="genglsl" />
-  <implementation name="IM_viewdir_vector3_genmsl" nodedef="ND_viewdir_vector3" target="genmsl" />
-  <nodegraph name="environmentDraw">
+  <nodegraph name="envMap">
 
     <!-- Get view direction -->
-    <viewdir name="viewDir" type="vector3" />
+    <viewdirection name="viewDir" type="vector3" />
 
     <!-- Compute longitude coordinate -->
     <atan2 name="angleXZ" type="float">
@@ -46,11 +39,11 @@
       <input name="in2" type="float" nodename="latitude" />
     </combine2>
     <image name="envImage" type="color3">
-      <input name="file" type="filename" value="resources/Lights/san_giuseppe_bridge.hdr" uniform="true" />
+      <input name="file" type="filename" value="resources/Lights/san_giuseppe_bridge.hdr" />
       <input name="texcoord" type="vector2" nodename="mapUvs" />
-      <input name="uaddressmode" type="string" value="periodic" uniform="true" />
-      <input name="vaddressmode" type="string" value="clamp" uniform="true" />
-      <input name="filtertype" type="string" value="linear" uniform="true" />
+      <input name="uaddressmode" type="string" value="periodic" />
+      <input name="vaddressmode" type="string" value="clamp" />
+      <input name="filtertype" type="string" value="linear" />
     </image>
 
     <!-- Return the resulting color -->

diff --git a/resources/Materials/TestSuite/_options.mtlx b/resources/Materials/TestSuite/_options.mtlx
@@ -91,7 +91,7 @@
     <input name="extraLibraryPaths" type="string" value="" />
 
     <!-- List of document paths for render tests -->
-    <input name="renderTestPaths" type="string" value="resources/Materials/Examples/StandardSurface,resources/Materials/TestSuite/stdlib/color_management,resources/Materials/TestSuite/stdlib/convolution,resources/Materials/TestSuite/stdlib/geometric,resources/Materials/TestSuite/stdlib/noise,resources/Materials/TestSuite/pbrlib" />
+    <input name="renderTestPaths" type="string" value="resources/Materials/Examples/StandardSurface,resources/Materials/TestSuite/stdlib/color_management,resources/Materials/TestSuite/stdlib/convolution,resources/Materials/TestSuite/stdlib/geometric,resources/Materials/TestSuite/stdlib/noise,resources/Materials/TestSuite/pbrlib,resources/Materials/TestSuite/nprlib" />
 
     <!-- Enable reference quality rendering. Default is false. -->
     <input name="enableReferenceQuality" type="boolean" value="false" />

diff --git a/resources/Materials/TestSuite/nprlib/edge_brighten.mtlx b/resources/Materials/TestSuite/nprlib/edge_brighten.mtlx
@@ -0,0 +1,28 @@
+<?xml version="1.0"?>
+<materialx version="1.38" colorspace="lin_rec709">
+  <nodegraph name="edge_brighten">
+    <viewdirection name="viewdirection_vector3" type="vector3" />
+    <normal name="normal_vector3" type="vector3" />
+    <multiply name="multiply_vector3" type="vector3">
+      <input name="in1" type="vector3" nodename="viewdirection_vector3" />
+      <input name="in2" type="float" value="-1" />
+    </multiply>
+    <dotproduct name="dotproduct_vector3" type="float">
+      <input name="in1" type="vector3" nodename="multiply_vector3" />
+      <input name="in2" type="vector3" nodename="normal_vector3" />
+    </dotproduct>
+    <clamp name="clamp_float" type="float">
+      <input name="in" type="float" nodename="dotproduct_vector3" />
+    </clamp>
+    <power name="power_float" type="float">
+      <input name="in1" type="float" nodename="clamp_float" />
+      <input name="in2" type="float" value="0.2" />
+    </power>
+    <mix name="mix_color3" type="color3">
+      <input name="fg" type="color3" value="0, 0.0986187, 0.186275" />
+      <input name="bg" type="color3" value="0.735294, 0.735294, 0.735294" />
+      <input name="mix" type="float" nodename="power_float" />
+    </mix>
+    <output name="out" type="color3" nodename="mix_color3" />
+  </nodegraph>
+</materialx>
diff --git a/resources/Materials/TestSuite/nprlib/starfield.mtlx b/resources/Materials/TestSuite/nprlib/starfield.mtlx
@@ -0,0 +1,25 @@
+<?xml version="1.0"?>
+<materialx version="1.38" colorspace="lin_rec709">
+  <nodegraph name="starfield">
+    <viewdirection name="viewDir" type="vector3" />
+    <multiply name="multiply_vector3FA" type="vector3">
+      <input name="in1" type="vector3" nodename="viewDir" />
+      <input name="in2" type="float" value="260" />
+    </multiply>
+    <noise3d name="noise3d_float" type="float">
+      <input name="position" type="vector3" nodename="multiply_vector3FA" />
+    </noise3d>
+    <contrast name="contrast_float" type="float">
+      <input name="in" type="float" nodename="noise3d_float" />
+      <input name="amount" type="float" value="5" />
+      <input name="pivot" type="float" value="0.8" />
+    </contrast>
+    <clamp name="clamp_float" type="float">
+      <input name="in" type="float" nodename="contrast_float" />
+    </clamp>
+    <convert name="convert_float_color3" type="color3">
+      <input name="in" type="float" nodename="clamp_float" />
+    </convert>
+    <output name="out" type="color3" nodename="convert_float_color3" />
+  </nodegraph>
+</materialx>
diff --git a/source/MaterialXGenGlsl/GlslShaderGenerator.cpp b/source/MaterialXGenGlsl/GlslShaderGenerator.cpp
@@ -14,6 +14,7 @@
 #include <MaterialXGenGlsl/Nodes/GeomPropValueNodeGlsl.h>
 #include <MaterialXGenGlsl/Nodes/FrameNodeGlsl.h>
 #include <MaterialXGenGlsl/Nodes/TimeNodeGlsl.h>
+#include <MaterialXGenGlsl/Nodes/ViewDirectionNodeGlsl.h>
 #include <MaterialXGenGlsl/Nodes/SurfaceNodeGlsl.h>
 #include <MaterialXGenGlsl/Nodes/UnlitSurfaceNodeGlsl.h>
 #include <MaterialXGenGlsl/Nodes/LightNodeGlsl.h>
@@ -196,6 +197,8 @@ GlslShaderGenerator::GlslShaderGenerator() :
     registerImplementation("IM_frame_float_" + GlslShaderGenerator::TARGET, FrameNodeGlsl::create);
     // <!-- <time> -->
     registerImplementation("IM_time_float_" + GlslShaderGenerator::TARGET, TimeNodeGlsl::create);
+    // <!-- <viewdirection> -->
+    registerImplementation("IM_viewdirection_vector3_" + GlslShaderGenerator::TARGET, ViewDirectionNodeGlsl::create);
 
     // <!-- <surface> -->
     registerImplementation("IM_surface_" + GlslShaderGenerator::TARGET, SurfaceNodeGlsl::create);

diff --git a/source/MaterialXGenGlsl/Nodes/ViewDirectionNodeGlsl.cpp b/source/MaterialXGenGlsl/Nodes/ViewDirectionNodeGlsl.cpp
@@ -0,0 +1,55 @@
+//
+// Copyright Contributors to the MaterialX Project
+// SPDX-License-Identifier: Apache-2.0
+//
+
+#include <MaterialXGenGlsl/Nodes/ViewDirectionNodeGlsl.h>
+
+#include <MaterialXGenShader/Shader.h>
+
+MATERIALX_NAMESPACE_BEGIN
+
+ShaderNodeImplPtr ViewDirectionNodeGlsl::create()
+{
+    return std::make_shared<ViewDirectionNodeGlsl>();
+}
+
+void ViewDirectionNodeGlsl::createVariables(const ShaderNode&, GenContext&, Shader& shader) const
+{
+    ShaderStage& vs = shader.getStage(Stage::VERTEX);
+    ShaderStage& ps = shader.getStage(Stage::PIXEL);
+
+    addStageInput(HW::VERTEX_INPUTS, Type::VECTOR3, HW::T_IN_POSITION, vs);
+    addStageConnector(HW::VERTEX_DATA, Type::VECTOR3, HW::T_POSITION_WORLD, vs, ps);
+    addStageUniform(HW::PRIVATE_UNIFORMS, Type::VECTOR3, HW::T_VIEW_POSITION, ps);
+}
+
+void ViewDirectionNodeGlsl::emitFunctionCall(const ShaderNode& node, GenContext& context, ShaderStage& stage) const
+{
+    const ShaderGenerator& shadergen = context.getShaderGenerator();
+
+    DEFINE_SHADER_STAGE(stage, Stage::VERTEX)
+    {
+        VariableBlock& vertexData = stage.getOutputBlock(HW::VERTEX_DATA);
+        const string prefix = vertexData.getInstance() + ".";
+        ShaderPort* position = vertexData[HW::T_POSITION_WORLD];
+        if (!position->isEmitted())
+        {
+            position->setEmitted();
+            shadergen.emitLine(prefix + position->getVariable() + " = hPositionWorld.xyz", stage);
+        }
+    }
+
+    DEFINE_SHADER_STAGE(stage, Stage::PIXEL)
+    {
+        VariableBlock& vertexData = stage.getInputBlock(HW::VERTEX_DATA);
+        const string prefix = vertexData.getInstance() + ".";
+        ShaderPort* position = vertexData[HW::T_POSITION_WORLD];
+        shadergen.emitLineBegin(stage);
+        shadergen.emitOutput(node.getOutput(), true, false, context, stage);
+        shadergen.emitString(" = normalize(" + prefix + position->getVariable() + " - " + HW::T_VIEW_POSITION + ")", stage);
+        shadergen.emitLineEnd(stage);
+    }
+}
+
+MATERIALX_NAMESPACE_END
diff --git a/source/MaterialXGenGlsl/Nodes/ViewDirectionNodeGlsl.h b/source/MaterialXGenGlsl/Nodes/ViewDirectionNodeGlsl.h
@@ -0,0 +1,26 @@
+//
+// Copyright Contributors to the MaterialX Project
+// SPDX-License-Identifier: Apache-2.0
+//
+
+#ifndef MATERIALX_VIEWDIRECTIONNODEGLSL_H
+#define MATERIALX_VIEWDIRECTIONNODEGLSL_H
+
+#include <MaterialXGenGlsl/GlslShaderGenerator.h>
+
+MATERIALX_NAMESPACE_BEGIN
+
+/// ViewDirection node implementation for GLSL
+class MX_GENGLSL_API ViewDirectionNodeGlsl : public GlslImplementation
+{
+  public:
+    static ShaderNodeImplPtr create();
+
+    void createVariables(const ShaderNode& node, GenContext& context, Shader& shader) const override;
+
+    void emitFunctionCall(const ShaderNode& node, GenContext& context, ShaderStage& stage) const override;
+};
+
+MATERIALX_NAMESPACE_END
+
+#endif
diff --git a/source/MaterialXGenMdl/mdl/materialx/stdlib.mdl b/source/MaterialXGenMdl/mdl/materialx/stdlib.mdl
@@ -1366,6 +1366,22 @@ export float mx_time_float(
 	return ::state::animation_time();
 }
 
+export float3 mx_viewdirection_vector3(
+	uniform mx_coordinatespace_type mxp_space = mx_coordinatespace_type(mx_coordinatespace_type_world)	
+	[[
+		anno::description("Enumeration {model,object,world}."),
+        anno::unused()
+	]]
+)
+	[[
+		anno::description("Node Group: nprlib")
+	]]
+{
+	// Not implemented: mx_viewdirection_vector3
+	float3 defaultValue = float3(0.0, 0.0, 1.0);
+	return defaultValue;
+}
+
 export color mx_modulo_color3(
 	color mxp_in1 = color(0.0, 0.0, 0.0),
 	color mxp_in2 = color(1.0, 1.0, 1.0)

diff --git a/source/MaterialXGenMsl/MslShaderGenerator.cpp b/source/MaterialXGenMsl/MslShaderGenerator.cpp
@@ -14,6 +14,7 @@
 #include <MaterialXGenMsl/Nodes/GeomPropValueNodeMsl.h>
 #include <MaterialXGenMsl/Nodes/FrameNodeMsl.h>
 #include <MaterialXGenMsl/Nodes/TimeNodeMsl.h>
+#include <MaterialXGenMsl/Nodes/ViewDirectionNodeMsl.h>
 #include <MaterialXGenMsl/Nodes/SurfaceNodeMsl.h>
 #include <MaterialXGenMsl/Nodes/UnlitSurfaceNodeMsl.h>
 #include <MaterialXGenMsl/Nodes/LightNodeMsl.h>
@@ -200,6 +201,8 @@ MslShaderGenerator::MslShaderGenerator() :
     registerImplementation("IM_frame_float_" + MslShaderGenerator::TARGET, FrameNodeMsl::create);
     // <!-- <time> -->
     registerImplementation("IM_time_float_" + MslShaderGenerator::TARGET, TimeNodeMsl::create);
+    // <!-- <viewdirection> -->
+    registerImplementation("IM_viewdirection_vector3_" + MslShaderGenerator::TARGET, ViewDirectionNodeMsl::create);
 
     // <!-- <surface> -->
     registerImplementation("IM_surface_" + MslShaderGenerator::TARGET, SurfaceNodeMsl::create);

diff --git a/source/MaterialXGenMsl/Nodes/ViewDirectionNodeMsl.cpp b/source/MaterialXGenMsl/Nodes/ViewDirectionNodeMsl.cpp
@@ -0,0 +1,55 @@
+//
+// Copyright Contributors to the MaterialX Project
+// SPDX-License-Identifier: Apache-2.0
+//
+
+#include <MaterialXGenMsl/Nodes/ViewDirectionNodeMsl.h>
+
+#include <MaterialXGenShader/Shader.h>
+
+MATERIALX_NAMESPACE_BEGIN
+
+ShaderNodeImplPtr ViewDirectionNodeMsl::create()
+{
+    return std::make_shared<ViewDirectionNodeMsl>();
+}
+
+void ViewDirectionNodeMsl::createVariables(const ShaderNode&, GenContext&, Shader& shader) const
+{
+    ShaderStage& vs = shader.getStage(Stage::VERTEX);
+    ShaderStage& ps = shader.getStage(Stage::PIXEL);
+
+    addStageInput(HW::VERTEX_INPUTS, Type::VECTOR3, HW::T_IN_POSITION, vs);
+    addStageConnector(HW::VERTEX_DATA, Type::VECTOR3, HW::T_POSITION_WORLD, vs, ps);
+    addStageUniform(HW::PRIVATE_UNIFORMS, Type::VECTOR3, HW::T_VIEW_POSITION, ps);
+}
+
+void ViewDirectionNodeMsl::emitFunctionCall(const ShaderNode& node, GenContext& context, ShaderStage& stage) const
+{
+    const ShaderGenerator& shadergen = context.getShaderGenerator();
+
+    DEFINE_SHADER_STAGE(stage, Stage::VERTEX)
+    {
+        VariableBlock& vertexData = stage.getOutputBlock(HW::VERTEX_DATA);
+        const string prefix = vertexData.getInstance() + ".";
+        ShaderPort* position = vertexData[HW::T_POSITION_WORLD];
+        if (!position->isEmitted())
+        {
+            position->setEmitted();
+            shadergen.emitLine(prefix + position->getVariable() + " = hPositionWorld.xyz", stage);
+        }
+    }
+
+    DEFINE_SHADER_STAGE(stage, Stage::PIXEL)
+    {
+        VariableBlock& vertexData = stage.getInputBlock(HW::VERTEX_DATA);
+        const string prefix = vertexData.getInstance() + ".";
+        ShaderPort* position = vertexData[HW::T_POSITION_WORLD];
+        shadergen.emitLineBegin(stage);
+        shadergen.emitOutput(node.getOutput(), true, false, context, stage);
+        shadergen.emitString(" = normalize(" + prefix + position->getVariable() + " - " + HW::T_VIEW_POSITION + ")", stage);
+        shadergen.emitLineEnd(stage);
+    }
+}
+
+MATERIALX_NAMESPACE_END