Creation of a .prc File

The topic describes how to create a .prc file and fill it with contents: file structures, global data, tessellation, geometry data, etc.

For creating a new .prc file with one file structure (one product definition and one file structure), use the following steps:

Create an instance of the OdPrcFile class (assuming that svcs is an instance of MyService class described in Create client applications):
```
          OdPrcFilePtr pFile = svcs.createObject();
        
```

Initialize the model file data section and set common information for the newly created file (minimal version for reading: the authoring version and units):


          pFile->setVersions(8137, 8137);
          pFile->modelFileData().unit().setUnitFromCADFile(true);
          pFile->modelFileData().unit().setUnit(1);

Generate a new unique identifier for the .prc file header (containing data section about file structures):
```
          pFile->fileStructureId() = OdPrcUniqueId::generateUID();
        
```

Get a reference to the file structures array of the created .prc file:


          OdPrcFileStructurePtrArray &fileStructures = pFile->fileStructures();

Create a new file structure, generate a unique identifier for it, and append it to the file structures array and to the .prc file:


          OdPrcFileStructurePtr newStructure = OdPrcFileStructure::createObject();
          newStructure->fileStructureId() = OdPrcUniqueId::generateUID();
          fileStructures.append(newStructure);
          pFile->addFileStructure(*newStructure);

Create a global data section for the new file structure and set tessellation data for it:

  
          OdPrcFileStructureGlobals& fileStructureGlobals = newStructure->fileStructureGlobals();
          fileStructureGlobals.setTessellationChordHeightRatio(2000);
          fileStructureGlobals.setTessellationAngleDegree(40);

Create a new part definition, add it to the newly created file structure, and push it to the end of the file structure tree:


          OdPrcPartDefinitionPtr newDefinition = OdPrcPartDefinition::createObject();
          newStructure->addObject(newDefinition);
          newStructure->fileStructureTree().partDefinition().push_back(newDefinition->objectId());

Create a new product occurrence section and make it correspond with the part definition created in the previous step:


          OdPrcProductOccurrencePtr newProductOccurrence = OdPrcProductOccurrence::createObject();
          newStructure->addObject(newProductOccurrence);
          newProductOccurrence->referencesOfProductOccurrence().setCorrespondingPartDefinition(newDefinition->objectId());
          newProductOccurrence->productInformation().unitInformation().setUnit(1);
          newStructure->fileStructureTree().productOccurrence().push_back(newProductOccurrence);

Make the created product occurrence the file structure root:

  
          newStructure->fileStructureTree().internalData().setRootProductOccurrence(newProductOccurrence->objectId());

Add an exact geometry section to the file section:


          OdPrcContextAndBodies newContextAndBodies;
          newContextAndBodies.topoContext().setBehaviour(6);
          newContextAndBodies.topoContext().setGranularity(1e-8);
          newContextAndBodies.topoContext().setTolerance(1e-6);
          newStructure->fileStructureGeometry().fileStructureExactGeometry().topologicalContext().push_back(newContextAndBodies);

Initialize the file structure header section by setting the minimal version for reading and authoring:
```
  
          newStructure->setVersions(8137, 8137);
        
```

Make the product occurrence the start root occurrence for the model file:


          pFile->modelFileData().addStartRootOccurrence(*newProductOccurrence);

See Also: