LOOKDEVX-2124 - MaterialX Topo Handler #3445
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Implements a topo neutral graph generator. This allows detecting that two native MaterialX shading graphs are topologically equivalent, generate universal shading code, and provide the right mapping to find the original node name corresponding to a renamed node. Also adds proper exports to allow rebuilding the old MaterialX Maya surface node using this new functionnality. This also requires fixing the generated code to properly handle the "texcoord" nodes variables used in the shader.
| @@ -65,6 +67,10 @@ mayaUsd_promoteHeaderList(HEADERS ${HEADERS} SUBDIR render/MaterialXGenOgsXml) | |||
| # install | |||
| # ----------------------------------------------------------------------------- | |||
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| install(FILES ${HEADERS} | |||
| DESTINATION ${CMAKE_INSTALL_PREFIX}/include/${PROJECT_NAME}/render/MaterialXGenOgsXml | |||
| ) | |||
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Allows LookdevX to used the shadergen code.
| static const std::regex primvarParamRegex(primvarParamSource.c_str()); | ||
| static const std::string texcoordParamSource | ||
| = "vec([23]) [$](" + d(HW::T_TEXCOORD) + "_[0-9]+)"; | ||
| static const std::regex texcoordParamRegex(texcoordParamSource.c_str()); |
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As you can see above, we already had code that cleaned up shader stream variable names that were generated for "geompropvalue" nodes. We need to do the same for variable names generated for the "texcoor"nodes used in LookdevX.
| @@ -462,7 +462,7 @@ bool OgsFragment::isElementAShader() const | |||
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| bool OgsFragment::isTransparent() const | |||
| { | |||
| return _glslShader && _glslShader->hasAttribute(mx::HW::ATTR_TRANSPARENT); | |||
| return isTransparentSurface(_element, mx::GlslShaderGenerator::TARGET); | |||
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Using native MaterialX call.
| @@ -16,7 +18,7 @@ namespace MaterialXMaya { | |||
| /// and outputs and embedding source code in one or potentially multiple target | |||
| /// shading languages (GLSL is the only such language currently supported). | |||
| /// | |||
| class OgsFragment | |||
| class MAYAUSD_CORE_PUBLIC OgsFragment | |||
| { | |||
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Allow these classes to be used in LookdevX.
| const std::string SURFACEMATERIAL_CATEGORY("surfacematerial"); | ||
| const std::string SURFACESHADER_TYPE("surfaceshader"); | ||
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| const std::set<std::string> _mtlxTopoNodeSet = { |
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Moved from material.cpp
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| TopoNeutralGraph::TopoNeutralGraph(const mx::ElementPtr& material) | ||
| { | ||
| if (!material) { |
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Having a look at the test cases really helps understand what this code is doing.
| mx::NodePtr TopoNeutralGraph::cloneNode(const mx::Node& node, mx::GraphElement& container) | ||
| { | ||
| auto destNode | ||
| = container.addNode(node.getCategory(), "N" + std::to_string(_nodeIndex), node.getType()); |
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All cloned nodes get incremental names starting at N0. This allows merging graphs that have the same nodes and connectivity, but differs in node names.
| </constant> | ||
| <output name="O0" type="float" channels="g" nodename="N2" /> | ||
| </nodegraph> | ||
| </materialx> |
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These are the output graphs from a topo neutral cloning. As you can see the ordering of the nodes, outputs, and names is extremely consistent, allowing comparing two of those graphs for equality.
| </standard_surface> | ||
| <surfacematerial name="Channel1" type="material" topo="Channel1_topo.mtlx"> | ||
| <input name="surfaceshader" type="surfaceshader" nodename="Surf1" /> | ||
| </surfacematerial> |
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These are all the test cases, the "topo" attribute on the "surfacematerial" node indicates which file contains the output we seek. As you can see quite a few of these graphs will end up with the same baseline topo result.
| auto destNode | ||
| = container.addNode(node.getCategory(), "N" + std::to_string(_nodeIndex), node.getType()); | ||
| ++_nodeIndex; | ||
| _nodeMap.insert({ node.getNamePath(), destNode }); |
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Looks like a small bug here. The second identical insert should be removed.
| if (materialNode->getType() != SURFACESHADER_TYPE) { | ||
| throw mx::Exception("Material shader node is not a surfaceshader."); | ||
| } | ||
| auto dupMaterial = _doc->addMaterialNode("N" + std::to_string(_nodeIndex)); |
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(super minor) - Not sure if it's a touch more intuitive to do _nodeIndex++ here instead of the later ++_nodeIndex. I think I saw this elsewhere as well. Just personal preference perhaps.
bc99160
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@seando-adsk ready for merge. |
Implements a topo neutral graph generator. This allows detecting that two native MaterialX shading graphs are topologically equivalent, generate universal shading code, and provide the right mapping to find the original node name corresponding to a renamed node.
Also adds proper exports to allow rebuilding the old MaterialX Maya surface node using this new functionnality. This also requires fixing the generated code to properly handle the "texcoord" nodes variables used in the shader.