A circle packing script in rhinoscript, for rhino 3d 4.0 only.

Circle Packing Script

Option Explicit
'Script written by Steven Janssen
'Script copyrighted by Steven Janssen
'Script version Sunday, 18 May 2008 11:34:18 AM

Call Main()
Sub Main()
	Dim arrPoint(), arrRadius(), intCircleNumber, arrInputR, arrSide(2)
	Dim strCurrentCircleID, R, intCurrentCentre, k
	Dim dblCosA, dblRotA
	Dim checkdistanceA, checkdistanceB, checkloop, marker, intHole
	
	'Get Input Circles
	arrInputR = Rhino.GetObjects("Select Circles", 4)
	If Not IsArray(arrInputR) Then
		Exit Sub
	End If
	
	'Get Radii from Input Circles
	For R = 0 To Ubound(arrInputR)
		If Rhino.IsCircle(arrInputR(R)) Then
			arrInputR(R) = Rhino.CircleRadius(arrInputR(R))
		End If
	Next
	
	intCircleNumber = Rhino.GetInteger("Number of Circles",1000)
	intCircleNumber = intCircleNumber - 1
	
	ReDim arrPoint(intCircleNumber)
	ReDim arrRadius(intCircleNumber)
	
	'Draw 1st Circle
	arrRadius(0) = arrInputR(Int(RND*(Ubound(arrInputR)+1)))
	arrPoint(0) = Rhino.GetPoint("Centre of Circle")
	If Not IsArray(arrPoint(0)) Then
		Exit Sub
	End If
	strCurrentCircleID = Rhino.AddCircle(Array(arrPoint(0),Array(1,0,0),Array(0,1,0),Array(0,0,1)),arrRadius(0))
	
	Rhino.EnableRedraw vbFalse

	'Draw 2nd Circle
	arrRadius(1) = arrInputR(Int(RND*(Ubound(arrInputR)+1)))
	arrPoint(1) = arrPoint(0)
	arrPoint(1)(0) = arrPoint(1)(0) + arrRadius(0) + arrRadius(1)
	strCurrentCircleID = Rhino.AddCircle(Array(arrPoint(1),Array(1,0,0),Array(0,1,0),Array(0,0,1)),arrRadius(1))
	
	intCurrentCentre = 0
	intHole = 1
	
	'Draw other Circles
	For k = 2 To intCircleNumber
		
		Rhino.StatusBarMessage k+1 & "/" & intCircleNumber+1
		arrRadius(k) = arrInputR(Int(RND*(Ubound(arrInputR)+1)))
		
		Do
			marker = 0
			
			'Calculate the lengths of the sides
			arrSide(0) = Rhino.distance(arrPoint(intCurrentCentre), arrPoint(k-intHole))
			arrSide(1) = arrRadius(k) + arrRadius(intCurrentCentre)
			arrSide(2) = arrRadius(k) + arrRadius(k-intHole)
		
			'Calculate Angle
			dblCosA = (arrSide(0)^2 + arrSide(1)^2 - arrSide(2)^2) / (2 * arrSide(0) * arrSide(1))

			If dblCosA > 1 Then
				marker = 1
			Else
				dblRotA = Atn(-dblCosA / Sqr((-dblCosA * dblCosA) + 1)) + (2 * Atn(1))
				dblRotA = Rhino.ToDegrees(dblRotA)
				
				'Create, rotate and scale Vector
				arrPoint(k) = Rhino.VectorCreate(arrPoint(k-intHole),arrPoint(intCurrentCentre))
				arrPoint(k) = Rhino.VectorRotate(arrPoint(k),dblRotA,Array(0,0,1))
				arrPoint(k) = Rhino.VectorScale(arrPoint(k),(arrSide(1)/arrSide(0)))
				arrPoint(k) = Rhino.VectorAdd(arrPoint(k),arrPoint(intCurrentCentre))
			
				'Check if Circle will Intersect with Existing Circles
				For checkloop = (k-1) To 0 Step -1
					checkdistanceA = Rhino.distance(arrPoint(k), arrPoint(checkloop)) + 0.001
					checkdistanceB = (arrRadius(k) + arrRadius(checkloop))
					If checkdistanceA < checkdistanceB Then
						marker = 1
						Exit For
					End If
				Next
				If marker = 0 Then
					'rhino.AddLine arrPoint(k-intHole), arrPoint(k)
					strCurrentCircleID = Rhino.AddCircle(Array(arrPoint(k),Array(1,0,0),Array(0,1,0),Array(0,0,1)),arrRadius(k))
				End If
			End If
			
			'Exit the Do Loop if the Circle is Good
			If marker = 0 Then
				intHole = 1
				Exit Do
			End If
			
			intCurrentCentre = intCurrentCentre + 1
			
			If intCurrentCentre = k-intHole Then
				intHole = intHole + 1
				intCurrentCentre = 0
				'If intHole > 2 Then
				'	rhino.addpoint arrPoint(k-intHole)
				'End If
				'rhino.messagebox intHole
			End If
			
		Loop	
	Next

	Rhino.EnableRedraw vbTrue

End Sub