Function SurfEvaluate

	Dim SurfObject: SurfObject = Rhino.GetObject("Select a surface",8)
	
	dim i
	dim UvalOne(1), UvalTwo
	dim SurfaceUone, SurfaceVone
	dim PointOne, PointTwo
	dim Pt1, Pt2, Pt3, Pt4
	dim NumVarU: NumVarU = 7
	dim NumVarV: NumVarV = 5
	dim FourPtCluster:  FourPtCluster=Array(Pt1,Pt2,Pt3,Pt4)
	redim Matrix (NumVarU, NumVarV)
	dim tempPt
	SurfaceUone = array (0,0)
	SurfaceVone = array (0,0)
	
	'select a surface and test to be sure it is a surface
	If Rhino.IsSurface(SurfObject) Then
		SurfaceUone = Rhino.SurfaceDomain(SurfObject, 0)
		SurfaceVone = Rhino.SurfaceDomain(SurfObject, 1)
		'Rhino.Print "Domain in U direction: " & CStr(SurfaceUone(0)) & " to " & CStr(SurfaceUone(1))
		'Rhino.Print "Domain in V direction: " & CStr(SurfaceVOne(0)) & " to " & CStr(SurfaceVOne(1))
	End If

	'create a 2-D array called Matrix to hold all the points along the surface
	'the variables NumVarU and NumVarV determine the number of segments the 
	'surface will be divided into in each direction
	for i=0 to NumVarU
		for j=0 to NumVarV
		UvalOne(0)=((SurfaceUone(1)-SurfaceUone(0))/NumVarU)*(i)
		UvalOne(1)=((SurfaceVone(1)-SurfaceVone(0))/NumVarV)*(j)
		
		PointOne=Rhino.EvaluateSurface(SurfObject,UvalOne)
		tempPt = Rhino.addpoint(PointOne) 'creates points to mark the divisions
		
		Matrix(i,j) = PointOne 'creates a "master" array which will pass points to another function
		'rhino.print Matrix (i,j)
		
		next
	next

	for i=0 to NumVarU-1
		for j=0 to NumVarV-1
		Pt1 = matrix(i,j)
		Pt2 = matrix(i+1,j)
		Pt3 = matrix(i+1,j+1)
		Pt4 = matrix(i,j+1)
		
		call Drawbox2(Pt1,Pt2,Pt3,Pt4)
		
		next

	next
		
end function



Function Drawbox2(Pt1,Pt2,Pt3,Pt4)

	dim tempsrf, arrDomainU, arrDomainV, arrDirection
	dim arrParam(1),arrNormal,LineNormSmall, LineNormBig, Pt5
	dim LineP1P4, LineP1P4extend, LineArray
	dim VertSurface
	tempsrf = rhino.addsrfpt (Array(pt1,pt2,pt3,pt4))
	'rhino.MoveObject tempsrf,pt1,pt3
	
	
	arrDomainU = Rhino.SurfaceDomain(tempsrf, 0)
	arrDomainV = Rhino.SurfaceDomain(tempsrf, 1)
	arrParam(0) =(arrDomainU(1)-arrDomainU(0))/2
	arrParam(1) =(arrDomainV(1)-arrDomainV(0))/2 
	Pt5 = Rhino.EvaluateSurface(tempsrf, arrParam)
	Rhino.AddPoint Pt5
	
	arrNormal = Rhino.SurfaceNormal (tempSrf, arrParam)
	LineNormSmall = Rhino.AddLine (arrNormal(0), arrNormal(1))
	LineNormBig = Rhino.ExtendCurveLength (LineNormSmall, 0,1,6*rnd)
	
	
	arrPtDomain = rhino.CurveDomain (LineNormBig)
	arrPtParam = arrPtDomain (1)
	Pt6 = Rhino.EvaluateCurve (LineNormBig,ArrPtParam)
	rhino.addpoint pt6
	
	LineP1P4 = rhino.addline (pt1,pt4)
	LineP1P2 = rhino.addline (pt1,pt2)
	LineP1P4Norm = rhino.copyObject (LineP1P4,pt5,pt6)
	LineP1P4Extend = Rhino.ExtendCurveLength (LineP1P4, 0,1,1)
	LineP1P2Extend = Rhino.ExtendCurveLength (LineP1P2, 0,1,2)
	LineArray = (array(LineP1P4Extend,LineP1P4Norm))
	VertSurface1 = Rhino.AddEdgeSrf (LineArray)				'creates surface between long line near surface and short line immediately above
	VertSurface2 = rhino.ExtrudeSurface (VertSurface1,LineP1P2Extend)	'creates a trapezoid using the surface just made, etruded along a long line
	
	LineNormHuge = Rhino.ExtendCurveLength (LineNormSmall, 0,1,40)
	Ellipse1 = rhino.addCurve (Array(Pt1,Pt2,Pt3,Pt4,Pt1))			'draws a curve, like an elipse, using 4 points 
	rhino.selectobject Ellipse1
	rhino.command ("-patch " & "enter")
	Ellipse2 = rhino.LastObject						'grabs the previously constructed elipse that has just been made into a surface
	Ellipse3 = rhino.Extrudesurface (Ellipse2,LineNormHuge)			'creates an extruded elipse to be subtracted from VertSurface2
	rhino.MoveObject Ellipse3,pt6,pt5
	rhino.MoveObject Ellipse3,pt6,pt5
	rhino.MoveObject Ellipse3,pt6,pt5
	rhino.MoveObject Ellipse3,pt6,pt5
	rhino.MoveObject Ellipse3,pt6,pt5
	
	ArrEllipse = (array(Ellipse3))
	ArrTrapezoid = (array(VertSurface2))
	rhino.BooleanDifference ArrTrapezoid,ArrEllipse
	
	rhino.unSelectAllObjects
	
End Function

call SurfEvaluate


''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
	'dim strCurve, StrPath

	'strCurve = Rhino.AddCircle(Array(0,0,0), 5)
	'strPath = Rhino.AddLine(Array(5,0,0), Array(10,0,10))
	'rhino.selectobject strCurve
	'rhino.command ("-patch " & "enter")