Overview

In this example demonstrates how to perform unfolding of 3D model using sheet metal unfolder tool (SheetMetal_Unfolder). For this purpose, used a console application that imports a model, collects unique ModelData::Part s, traverses through unique ModelData::Part s, creates and runs SheetMetal_Unfolder, prints information about flat pattern parameters into console.

Unfolding will be performed for each unique ModelData::Part , but only for the scope of accepted geometries.

Application needs one input arguments to run:

Usage: sheet_metal_unfolder <input_file>, where:

<input_file> is a name of the file to be read

For more information about unfolding visit Sheet Metal Unfolding page.

Implementation

To explore the model and process ModelData::Part s, it's need to create an inheritor from the ModelData::ModelElementVoidVisitor and override the part processing method void operator() (const ModelData::Part& thePart). For this purpose, the PartProcessor class was created. In operator() method a ModelData::Part is examined for the presence of B-Rep Geometry and Topology B-Rep Geometry and ModelData::Solid or ModelData::Shell shapes in it.

void operator() (const ModelData::Part& thePart) override
{
    auto aPartName = thePart.Name().IsEmpty() ? "noname" : thePart.Name();
 
    size_t aBodyNumber = 0;
    auto aBodies = thePart.GetBodies();
    for (const auto& aBody : aBodies) {
        ModelData::ShapeIterator aShapeIt (aBody);
        while (aShapeIt.HasNext()) {
            const auto& aShape = aShapeIt.Next();
            if (aShape.Type() == ModelData::ShapeType::Solid) {
                cout << "Part #" << myPartIndex << " [\"" << aPartName << "\"] - solid #" << std::to_string (aBodyNumber) << " has:" << endl;
                ProcessSolid (ModelData::Solid::Cast (aShape), aPartName, aBodyNumber);
            } else if (aShape.Type() == ModelData::ShapeType::Shell) {
                cout << "Part #" << myPartIndex << " [\"" << aPartName << "\"] - shell #" << std::to_string (aBodyNumber) << " has:" << endl;
                ProcessShell (ModelData::Shell::Cast (aShape), aPartName, aBodyNumber);
            }
        }
        ++aBodyNumber;
    }
 
    ++myPartIndex;
}

ProcessSolid and ProcessShell methods are used to run sheet metal unfolder for given entities.

void ProcessSolid (const ModelData::Solid& theSolid, const UTF16String& /*thePartName*/, size_t /*theShapeIndex*/)
{
    auto aFlatPattern = myUnfolder.Perform (theSolid);
    PrintFlatPatternInfo (aFlatPattern);
}
 
void ProcessShell (const ModelData::Shell& theShell, const UTF16String& /*thePartName*/, size_t /*theShapeIndex*/)
{
    auto aFlatPattern = myUnfolder.Perform (theShell);
    PrintFlatPatternInfo (aFlatPattern);
}

To traverse only unique parts of the imported model, the ModelData::ModelElementUniqueVisitor class is used.

PartProcessor aPartProcessor ();
ModelData::ModelElementUniqueVisitor aVisitor (aPartProcessor);
aModel.Accept (aVisitor);

Method PrintFlatPattern is used to explore and print flat pattern parameters.

void PrintFlatPattern (const SheetMetal_FlatPattern& theFlatPattern)
{
    cout << "    Flat Pattern with:" << endl;
    cout << "          length: "    << theFlatPattern.Length()    << " mm" << endl;
    cout << "          width: "     << theFlatPattern.Width()     << " mm" << endl;
    cout << "          thickness: " << theFlatPattern.Thickness() << " mm" << endl;
    cout << "          perimeter: " << theFlatPattern.Perimeter() << " mm" << endl;
}

Example output

Below is the example output for model from ./examples/models/Part2.stp.

Model: Part2 Part #0 ["Part2"] - solid #0 has: Flat Pattern with: length: 220.712 mm width: 167.838 mm thickness: 1 mm perimeter: 1121.37 mm
Original model	Unfolded view

Table of Contents

Overview

Implementation

Example output

Files