RangeBox of components

<?xml encoding=”UTF-8″>By Adam Nagy

If you want to get the extents of a ComponentOccurrence then you can use its RangeBox for that.
This will provide the information in the coordinate system of the top assembly:

Sub AddPoints1( _
oCD As AssemblyComponentDefinition, oOcc As ComponentOccurrence)
Dim pt1 As Point
Set pt1 = oOcc.RangeBox.MinPoint
Dim pt2 As Point
Set pt2 = oOcc.RangeBox.MaxPoint
Call oCD.WorkPoints.AddFixed(pt1)
Call oCD.WorkPoints.AddFixed(pt2)
End Sub
Sub ComponentExtents1()
Dim oDoc As AssemblyDocument
Set oDoc = ThisApplication.ActiveDocument
Dim oCD As AssemblyComponentDefinition
Set oCD = oDoc.ComponentDefinition
Dim oOcc As ComponentOccurrence
For Each oOcc In oCD.Occurrences.AllLeafOccurrences
Call AddPoints1(oCD, oOcc)
Next
End Sub

If you want to get the extents in the part’s or subassembly’s coordinate system instead then you just have to drill down to the ComponentDefinition used by the occurrence, which will also have a RangeBox property. Then to show those points in the top assemblies coordinate system, you just have to transform them based on the occurrence’s Transformation property:

Sub AddPoints2( _
oCD As AssemblyComponentDefinition, oOcc As ComponentOccurrence)
Dim oRB As Box
Set oRB = oOcc.Definition.RangeBox
Dim pt1 As Point
Set pt1 = oRB.MinPoint
Call pt1.TransformBy(oOcc.Transformation)
Dim pt2 As Point
Set pt2 = oRB.MaxPoint
Call pt2.TransformBy(oOcc.Transformation)
Call oCD.WorkPoints.AddFixed(pt1)
Call oCD.WorkPoints.AddFixed(pt2)
End Sub
Sub ComponentExtents2()
Dim oDoc As AssemblyDocument
Set oDoc = ThisApplication.ActiveDocument
Dim oCD As AssemblyComponentDefinition
Set oCD = oDoc.ComponentDefinition
Dim oOcc As ComponentOccurrence
For Each oOcc In oCD.Occurrences.AllLeafOccurrences
Call AddPoints2(oCD, oOcc)
Next
End Sub

You could also get the extents in an arbitrary coordinate system, e.g. one defined by a UserCoordinateSystem object placed inside the part document. In this case we can use TransientBRep to transform the SurfaceBodies of the parts as also shown in this forum thread:  

Sub GetRangePoints3( _
oOcc As ComponentOccurrence, pt1 As Point, pt2 As Point)
Dim oUCS As UserCoordinateSystem
On Error Resume Next
Set oUCS = oOcc.Definition.UserCoordinateSystems("UCS")
On Error GoTo 0
' If the part does not have a UserCoordinateSystem object
' named "UCS" then we just use the part's coordinate system
If oUCS Is Nothing Then
Set pt1 = oOcc.Definition.RangeBox.MinPoint
Set pt2 = oOcc.Definition.RangeBox.MaxPoint
Exit Sub
End If
Dim oTB As TransientBRep
Set oTB = ThisApplication.TransientBRep
Dim oUT As Matrix
Set oUT = oUCS.Transformation
Call oUT.Invert
Dim oSB As SurfaceBody
Dim oTSB As SurfaceBody
Dim oRB As Box
For Each oSB In oOcc.Definition.SurfaceBodies
Set oTSB = oTB.Copy(oSB)
Call oTB.Transform(oTSB, oUT)
If oRB Is Nothing Then
Set oRB = oTSB.RangeBox
Else
Call oRB.Extend(oTSB.RangeBox.MinPoint)
Call oRB.Extend(oTSB.RangeBox.MaxPoint)
End If
Next
' Transform points back to the part coordinate system
Call oUT.Invert
Set pt1 = oRB.MinPoint
Call pt1.TransformBy(oUT)
Set pt2 = oRB.MaxPoint
Call pt2.TransformBy(oUT)
End Sub
Sub AddPoints3( _
oCD As AssemblyComponentDefinition, oOcc As ComponentOccurrence)
Dim pt1 As Point
Dim pt2 As Point
Call GetRangePoints3(oOcc, pt1, pt2)
Call pt1.TransformBy(oOcc.Transformation)
Call pt2.TransformBy(oOcc.Transformation)
Call oCD.WorkPoints.AddFixed(pt1)
Call oCD.WorkPoints.AddFixed(pt2)
End Sub
Sub ComponentExtents3()
Dim oDoc As AssemblyDocument
Set oDoc = ThisApplication.ActiveDocument
Dim oCD As AssemblyComponentDefinition
Set oCD = oDoc.ComponentDefinition
Dim oOcc As ComponentOccurrence
For Each oOcc In oCD.Occurrences.AllLeafOccurrences
Call AddPoints3(oCD, oOcc)
Next
End Sub

The following article might also come handy in understanding the component transformations:
http://adndevblog.typepad.com/manufacturing/2013/07/occurrences-contexts-definitions-proxies.html