Create Mesh from Solid

[Markus67]

Hello,

I try to migrate our ObjectArx Api to Inventor. Therefore I need a function to create a mesh from a solid.

With Autocad .Net Api, I can use GetObjectMesh(DbObject obj, MeshFaceterData parameter). Does in the Inventor Api a similiar function exist?

In the parameters I need to set the deviation in the same way as in the Autocad .Net Api.

Example:

FaceterDevNormal = 0.1;

FaceterDevSurface = 0.1;

FaceterMeshType = 2;

Thanks for further help.

Regards,

Markus

[philippe.leefsma]

Hi Markus,

There isn't a way to set the deviation similarly than in AutoCAD, but you need to use the "CalculateFacets" API where you can specify a tolerance. Below is a VBA sample, it can be used on SurfaceBody or Face objects, client graphics are used to visualize the result:

Public Sub GenerateFacets(facetable As Variant)

    Dim tolerance As Double
    Dim VertexCount As Long
    Dim FacetCount As Long
    Dim VertexCoords() As Double
    Dim normals() As Double
    Dim Indices() As Long
    
    tolerance = 0.003
    Call facetable.CalculateFacets(tolerance, VertexCount, FacetCount, VertexCoords, normals, Indices)
    
    Dim nbTriangles As Long
    nbTriangles = 0

    Dim i As Integer
    For i = 0 To UBound(Indices) Step 3
    
        Dim vIndex1 As Integer
        Dim vIndex2 As Integer
        Dim vIndex3 As Integer
        
        vIndex1 = (Indices(i) - 1) * 3
        vIndex2 = (Indices(i + 1) - 1) * 3
        vIndex3 = (Indices(i + 2) - 1) * 3

        Dim vertex1(2) As Double
        Dim vertex2(2) As Double
        Dim vertex3(2) As Double
        
        vertex1(0) = VertexCoords(vIndex1)
        vertex1(1) = VertexCoords(vIndex1 + 1)
        vertex1(2) = VertexCoords(vIndex1 + 2)
        
        vertex2(0) = VertexCoords(vIndex2)
        vertex2(1) = VertexCoords(vIndex2 + 1)
        vertex2(2) = VertexCoords(vIndex2 + 2)
        
        vertex3(0) = VertexCoords(vIndex3)
        vertex3(1) = VertexCoords(vIndex3 + 1)
        vertex3(2) = VertexCoords(vIndex3 + 2)
        
        'Call custom method to visualize facet edges
        Call DrawLineGraphics(vertex1, vertex2)
        Call DrawLineGraphics(vertex2, vertex3)
        Call DrawLineGraphics(vertex3, vertex1)
        
        nbTriangles = nbTriangles + 1
        
    Next
    
    ThisApplication.ActiveView.Update
   
End Sub

Public Sub DrawLineGraphics(startpt() As Double, endpt() As Double)

    Dim doc As Document
    Set doc = ThisApplication.ActiveDocument
    
    Dim compDef As ComponentDefinition
    Set compDef = doc.ComponentDefinition
       
    On Error Resume Next
       
    Dim dataSets As GraphicsDataSets
    Set dataSets = doc.GraphicsDataSetsCollection("LineGraphics")
    
    Dim clientGraphics As clientGraphics
    Set clientGraphics = compDef.ClientGraphicsCollection("LineGraphics")
    
    If Err Then
        Err.clear
        Set dataSets = doc.GraphicsDataSetsCollection.Add("LineGraphics")
        Set clientGraphics = compDef.ClientGraphicsCollection.Add("LineGraphics")
        
        Call dataSets.CreateCoordinateSet(1)
        Call clientGraphics.AddNode(1)
        Call clientGraphics(1).AddLineGraphics
    End If
    
    On Error GoTo 0
    
    Dim coordSet As GraphicsCoordinateSet
    Set coordSet = dataSets(1)

    Dim coords() As Double
    
    Call coordSet.GetCoordinates(coords)
    
    Dim idx As Long
    idx = 3 * coordSet.count
    
    ReDim Preserve coords(0 To idx + 5)
    
    coords(idx) = startpt(0)
    coords(idx + 1) = startpt(1)
    coords(idx + 2) = startpt(2)
    
    coords(idx + 3) = endpt(0)
    coords(idx + 4) = endpt(1)
    coords(idx + 5) = endpt(2)
    
    Call coordSet.PutCoordinates(coords)
                                               
    Dim lineGraphics As lineGraphics
    Set lineGraphics = clientGraphics(1).item(1)
    
    lineGraphics.CoordinateSet = coordSet
    
End Sub

Regards,

Philippe.