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 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.

def __call__(self, thePart: mtk.Part):
    aPartName = "noname" if thePart.Name().IsEmpty() else str(thePart.Name())
    aBodyList = thePart.Bodies()
    i = 0
    for aBody in aBodyList:
        aShapeIt = mtk.ShapeIterator(aBody)
        for aShape in aShapeIt:
            if aShape.Type() == mtk.ShapeType_Solid:
                print("Part #", self.myPartIndex, " [\"", aPartName, "\"] - solid #", i, " has:", sep="")
                self.ProcessSolid(mtk.Solid.Cast(aShape), aPartName, i)
                i += 1
            elif aShape.Type() == mtk.ShapeType_Shell:
                print("Part #", self.myPartIndex, " [\"", aPartName, "\"] - shell #", i, " has:", sep="")
                self.ProcessShell(mtk.Shell.Cast (aShape), aPartName, i)
                i += 1
    self.myPartIndex += 1

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

def ProcessSolid(self, theSolid: mtk.Solid, thePartName: str, theShapeIndex: int):
    aFlatPattern = self.myUnfolder.Perform(theSolid)
    PrintFlatPatternInfo(aFlatPattern)
 
def ProcessShell(self, theShell: mtk.Shell, thePartName: str, theShapeIndex: int):
    aFlatPattern = self.myUnfolder.Perform(theShell)
    PrintFlatPatternInfo(aFlatPattern)

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

aPartProcessor = PartProcessor()
aVisitor = mtk.ModelData_ModelElementUniqueVisitor(aPartProcessor)
aModel.Accept(aVisitor)

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

def PrintFlatPattern(theFlatPattern: mtk.SheetMetal_FlatPattern):
    if theFlatPattern.IsNull():
        print("    Failed to create flat pattern.")
        return
    
    print("    Flat Pattern with:")
    print("          length: ",    theFlatPattern.Length(),    " mm", sep="")
    print("          width: ",     theFlatPattern.Width(),     " mm", sep="")
    print("          thickness: ", theFlatPattern.Thickness(), " mm", sep="")
    print("          perimeter: ", theFlatPattern.Perimeter(), " mm", sep="")

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