ProtobufToMaterialX Class Reference

Converter class to transform Protobuf MaterialXDocument messages back into MaterialX document objects. More...

#include <materialx_serializer.h>

Public Member Functions
mx::DocumentPtr	convert (const MaterialXDocument &pb_doc)
	Convert a Protobuf MaterialXDocument message to a MaterialX document object.

Private Member Functions
mx::DocumentPtr	checkVersionAndUpgrade (const MaterialXDocument &pb_doc)
	Check schema version and perform upgrades if necessary.
mx::ElementPtr	convertElement (const MaterialXElement &pb_elem, mx::ElementPtr parent)
	Recursively convert a Protobuf MaterialXElement to a MaterialX element.

Detailed Description

Converter class to transform Protobuf MaterialXDocument messages back into MaterialX document objects.

• Traverses the Protobuf message structure and reconstructs the corresponding MaterialX document hierarchy.
• Handles attributes and child elements recursively.
• Requires the MaterialX C++ API to create and manipulate document elements.
• Usage: ProtobufToMaterialX converter; mx::DocumentPtr mx_doc = converter.convert(pb_doc);
• Where pb_doc is a MaterialXDocument Protobuf message.

Member Function Documentation

checkVersionAndUpgrade()

mx::DocumentPtr ProtobufToMaterialX::checkVersionAndUpgrade ( const MaterialXDocument & pb_doc )

private

Check schema version and perform upgrades if necessary.

Parameters

pb_doc

The Protobuf MaterialXDocument message.

Returns

A new MaterialX document pointer.

                                                                                         {
    mx::DocumentPtr doc = mx::createDocument();
    
    // Check if version is set
    if (pb_doc.has_schema_version()) {
        uint32_t major = pb_doc.schema_version().major();
        uint32_t minor = pb_doc.schema_version().minor();
        uint32_t patch = pb_doc.schema_version().patch();
        
        // Version compatibility check
        if (major > SCHEMA_VERSION_MAJOR) {
            std::ostringstream oss;
            oss << "Document schema version " << major << "." << minor << "." << patch
                << " is newer than supported version " 
                << SCHEMA_VERSION_MAJOR << "." << SCHEMA_VERSION_MINOR << "." << SCHEMA_VERSION_PATCH
                << ". Please upgrade your software.";
            throw std::runtime_error(oss.str());
        }
        
        // Perform upgrades for older versions
        if (major < SCHEMA_VERSION_MAJOR) {
            std::cout << "Warning: Upgrading document from version " 
                      << major << "." << minor << "." << patch
                      << " to " << SCHEMA_VERSION_MAJOR << "." 
                      << SCHEMA_VERSION_MINOR << "." << SCHEMA_VERSION_PATCH << std::endl;
            // Add upgrade logic here when needed
        }
    } else {
        // No version info - assume oldest supported version
        std::cout << "Warning: Document has no schema version information. Assuming legacy format." << std::endl;
    }
    
    return doc;
}

convert()

mx::DocumentPtr ProtobufToMaterialX::convert

(

const MaterialXDocument &

pb_doc

)

Convert a Protobuf MaterialXDocument message to a MaterialX document object.

Parameters

pb_doc

The Protobuf MaterialXDocument message to convert.

Returns

The reconstructed MaterialX document pointer.

                                                                          {
    // Check version compatibility and upgrade if needed
    mx::DocumentPtr doc = checkVersionAndUpgrade(pb_doc);
    
    // Set document attributes
    for (const Attribute& pb_attribute : pb_doc.attributes()) {
        doc->setAttribute(pb_attribute.key(), pb_attribute.value());
    }
    
    // Convert all elements
    for (const MaterialXElement& pb_element : pb_doc.elements()) {
        convertElement(pb_element, doc);
    }
    
    return doc;
}

convertElement()

mx::ElementPtr ProtobufToMaterialX::convertElement ( const MaterialXElement & pb_elem, mx::ElementPtr parent )

private

Recursively convert a Protobuf MaterialXElement to a MaterialX element.

Parameters

pb_elem	The Protobuf MaterialXElement message to convert.
parent	The parent MaterialX element to which the new element will be added.

Returns

The newly created MaterialX element pointer.

                                                                                                     {
    // Create element
    mx::ElementPtr mx_elem = parent->addChildOfCategory(pb_elem.type(), pb_elem.name());
    
    // Set all attributes preserving order
    for (const Attribute& attr : pb_elem.attributes()) {
        mx_elem->setAttribute(attr.key(), attr.value());
    }
    
    // Recursively convert children
    for (const MaterialXElement& pb_child : pb_elem.children()) {
        convertElement(pb_child, mx_elem);
    }
    
    return mx_elem;
}

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The documentation for this class was generated from the following files:

• materialx_serializer.h
• materialx_serializer.cpp