Overview

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 you need to derive a class from the ModelData.ModelElementVoidVisitor and override the part processing method void operator() (const ModelData::Part& thePart). In this example we use the PartProcessor class for this purpose. The operator() method is implemented to check each ModelData.Part for the presence of B-Rep Geometry and ModelData.Solid or ModelData.Shell shapes in it.

public override void Apply(Part thePart)
{
    string aPartName = thePart.Name().IsEmpty() ? "noname" : thePart.Name().ToString();
 
    var aBodyVec = thePart.Bodies();
    if (aBodyVec.Count != 0)
    {
        // Looking for a suitable body
        for (int i = 0; i < aBodyVec.Count; ++i)
        {
            Body aBody = aBodyVec[i];
 
            var aShapeIt = new ShapeIterator(aBody);
            while (aShapeIt.HasNext())
            {
                var aShape = aShapeIt.Next();
                if (aShape.Type() == ShapeType.Solid)
                {
                    Console.Write($"Part #{myPartIndex} [\"{aPartName}\"] - solid #{i} has:\n");
                    ProcessSolid(Solid.Cast(aShape), aPartName, i);
                }
                else if (aShape.Type() == ShapeType.Shell)
                {
                    Console.Write($"Part #{myPartIndex} [\"{aPartName}\"] - shell #{i} has:\n");
                    ProcessShell(Shell.Cast(aShape), aPartName, i);
                }
            }
        }
    }
 
    ++myPartIndex;
}

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

public void ProcessSolid(Solid theSolid, string thePartName, int theShapeIndex)
{
    SheetMetal_FlatPattern aFlatPattern = myUnfolder.Perform(theSolid);
    PrintFlatPatternInfo(aFlatPattern);
}
 
public void ProcessShell(Shell theShell, string thePartName, int theShapeIndex)
{
    SheetMetal_FlatPattern aFlatPattern = myUnfolder.Perform(theShell);
    PrintFlatPatternInfo(aFlatPattern);
}

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

var aPartProcessor = new PartProcessor();
var aVisitor = new ModelData.ModelElementUniqueVisitor(aPartProcessor);
aModel.Accept(aVisitor);

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

static void PrintFlatPattern(SheetMetal_FlatPattern theFlatPattern)
{
    if (theFlatPattern.IsNull())
    {
        Console.WriteLine($"    Failed to create flat pattern.");
        return;
    }
 
    Console.WriteLine($"    Flat Pattern with:");
    Console.WriteLine($"          length: {theFlatPattern.Length()} mm");
    Console.WriteLine($"          width: {theFlatPattern.Width()} mm");
    Console.WriteLine($"          thickness: {theFlatPattern.Thickness()} mm");
    Console.WriteLine($"          perimeter: {theFlatPattern.Perimeter()} mm");
}

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