Random animations are always nothing more than a good procedure which must be able to run for always and must be able to calculate certain random values. In our case the randomely calculated values are the points (X,Y,Z). Its not my procedure, copied here from a book called Flash Math. The original procedure is by some other guy and he used it in Flash to create such marvellous animation that stunned me four years ago when I's used to be a geek of Flash. The procedure is great and does nothing but calculate x,y,z according to the settings the user give it.
I used this procedure in VB very easily. The first phase is to make a shape that must reside in memory (for better and fast calculations). This is not a problem to do. Lots of ways are there. First of all there is a possiblity of using Region which can be very easy to create, just one command and you are done, but the problem with my style is I always choose the difficult way. So I choosed creating a DIB Section. A DIB Section is obviously not required of any introduction now. Then the second phase was how to change the colours randomely. For that problem I used simple GetDIBits and SetDIBits, and when it comes to random colours Rnd() * 255 is the best way to do it. Many of you may think whether GetDIBits and SetDIBits will prove to be that fast as we're talking in terms of a trail which is timed with the precission of only 40 milliseconds. So I've the answer, the SetDIBits methode is enough fast to edit an image of arround 500x500 in not more than 31 milliseconds and we used a DIB Section of 200x200 pixels which cuts the time to its half.
I inserted another good feature in this animation that it uses a user-defined BMP(32-bit) as the shape container. It makes quite easy for the program to just change the BMP and see great results. I think its enough talking lets start coding..

' Types Declaration Private Type BITMAP         bmType As Long         bmWidth As Long         bmHeight As Long         bmWidthBytes As Long         bmPlanes As Integer         bmBitsPixel As Integer         bmBits As Long End Type Private Type BITMAPINFOHEADER     biSize As Long     biWidth As Long     biHeight As Long     biPlanes As Integer     biBitCount As Integer     biCompression As Long     biSizeImage As Long     biXPelsPerMeter As Long     biYPelsPerMeter As Long     biClrUsed As Long     biClrImportant As Long End Type Private Type BLENDFUNCTION   BlendOp As Byte   BlendFlags As Byte   SourceConstantAlpha As Byte   AlphaFormat As Byte End Type ' APIs Declaration Private Declare Function VarPtrArray Lib "msvbvm60.dll" Alias "VarPtr" (Ptr() As Any) As Long Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (lpvDest As Any, lpvSource As Any, ByVal cbCopy As Long) Private Declare Function DeleteDC Lib "gdi32" (ByVal hdc As Long) As Long Private Declare Function DeleteObject Lib "gdi32.dll" (ByVal hObject As Long) As Long Private Declare Function GetDIBits Lib "gdi32" (ByVal aHDC As Long, ByVal hBitmap As Long, ByVal nStartScan As Long, ByVal nNumScans As Long, lpBits As Any, lpBI As BITMAPINFOHEADER, ByVal wUsage As Long) As Long Private Declare Function SetDIBits Lib "gdi32" (ByVal hdc As Long, ByVal hBitmap As Long, ByVal nStartScan As Long, ByVal nNumScans As Long, lpBits As Any, lpBI As BITMAPINFOHEADER, ByVal wUsage As Long) As Long Private Declare Function LoadImage Lib "user32" Alias "LoadImageA" (ByVal hInst As Long, ByVal lpsz As String, ByVal un1 As Long, ByVal n1 As Long, ByVal n2 As Long, ByVal un2 As Long) As Long Private Declare Function GetObject Lib "gdi32" Alias "GetObjectA" (ByVal hObject As Long, ByVal nCount As Long, lpObject As Any) As Long Private Declare Function AlphaBlend Lib "MSIMG32.DLL" (ByVal hdcDest As Long, ByVal nXOriginDest As Long, ByVal nYOriginDest As Long, ByVal nWidthDest As Long, ByVal nHeightDest As Long, ByVal hdcSrc As Long, ByVal nXOriginSrc As Long, ByVal nYOriginSrc As Long, ByVal nWidthSrc As Long, ByVal nHeightSrc As Long, ByVal lBlendFunction As Long) As Long Private Declare Function CreateCompatibleDC Lib "gdi32" (ByVal hdc As Long) As Long Private Declare Function SelectObject Lib "gdi32" (ByVal hdc As Long, ByVal hObject As Long) As Long Private Declare Function GetWindowDC Lib "user32" (ByVal hwnd As Long) As Long Private Declare Function GetTickCount Lib "kernel32" () As Long ' Constants Declaration Private Const BI_RGB = 0& Private Const DIB_RGB_COLORS = 0 Private Const LR_LOADFROMFILE = &H10 Private Const LR_CREATEDIBSECTION = &H2000 Private Const AC_SRC_OVER = &H0 Private Const AC_SRC_ALPHA = &H1 ' Personal Declaration Dim DIB As Long, OldDIB As Long, DC As Long, ti As Long Dim Pixel() As Byte Dim BM As BITMAP, BIH As BITMAPINFOHEADER Dim x0 As Double, y0 As Double, Z0 As Double Dim h As Double, a As Double, b As Double, c As Double Dim nxscale As Long, nyscale As Long, lBlend As Long Dim bf As BLENDFUNCTION Dim deskDC As Long, ColRed As Long, ColGreen As Long, ColBlue As Long Private Sub Command1_Click() Form1.Hide ti = GetTickCount() Timer2.Enabled = True Call Timer2_Timer Timer1.Enabled = True End Sub Private Sub Form_Load() DC = CreateCompatibleDC(0) ' Container DC If DC <> 0 Then     ' Loading the 32-BIT BMP called Shape1.bmp residing in the Application Directory     DIB = LoadImage(ByVal 0&, App.Path & "\Shape1.bmp", 0, 0, 0, LR_LOADFROMFILE Or LR_CREATEDIBSECTION)     If DIB <> 0 Then         GetObject DIB, Len(BM), BM ' Getting the properties for the loaded BMP         OldDIB = SelectObject(DC, DIB) ' Selecting the loaded bmp in the DC         With BIH ' Filling the BITMAPINFORHEADER             .biSize = 40             .biPlanes = 1             .biHeight = -BM.bmHeight             .biWidth = BM.bmWidth             .biBitCount = BM.bmBitsPixel         End With         ReDim Pixel(1 To 4, 1 To BM.bmWidth, 1 To BM.bmHeight) As Byte ' Redifing the Array to the new limits         Call GetDIBits(DC, DIB, 0&, BM.bmHeight, Pixel(1, 1, 1), BIH, 0) ' Getting the Pixels         ' Pixel(1,x,y) = Blue, Pixel(2,x,y) = Green , Pixel(3,x,y) = Red,Pixel(4,x,y) = Alpha Channel          ' Following are the few settings must be made for the Animation routine to follow         x0 = 6         y0 = 2         Z0 = 10         h = 0.009         a = 13         b = 30         c = 8# / 2#         ' DeskDC is the DC where the Animation will be shown         deskDC = GetWindowDC(0)         ' Following is the required structure for AlphaBlend API which does nothing more than BitBlt except it takes an extra  transparency element         With bf               .BlendOp = AC_SRC_OVER               .BlendFlags = 0               .SourceConstantAlpha = 50               .AlphaFormat = AC_SRC_ALPHA         End With         CopyMemory lBlend, bf, 4 ' Just like wraping the whole structure in a single variable so that we may pass this variable to the API     Else         MsgBox "Error"     End If End If End Sub Private Sub Timer1_Timer() ' With the precision of 40 milliseconds. ' Calculating new (x,y,z) X1 = x0 + h * a * (y0 - x0) Y1 = y0 + h * (x0 * (b - Z0) - y0) Z1 = Z0 + h * (x0 * y0 - c * Z0) ' Calculating new width and height based upon the z value nxscale = Z0 * 6 nyscale = Z0 * 6 ' Finally calling the AlphaBlend API to copy the Picture on the Desktop at the calculated x,y Call AlphaBlend(deskDC, (x0 * 10 + 180) + 50, (y0 * 10 + 180), nxscale, nyscale, DC, 0, 0, BM.bmWidth, BM.bmHeight, lBlend) x0 = X1 y0 = Y1 Z0 = Z1 ' Following is a trick to stop the animation after almost 10 seconds If (GetTickCount() - ti) = 10000 Then Timer1.Enabled = False Timer2.Enabled = False Form1.Show End If End Sub Private Sub Timer2_Timer() ' Schedualed up 800 milliseconds. It changes the colour of the Shape Dim Alpha As Long, Dis As Double, x As Long, y As Long ' Following is the way we calculate the random colour. ColRed = Rnd() * 255 ColGreen = Rnd() * 255 ColBlue = Rnd() * 255 For y = 1 To BM.bmHeight     For x = 1 To BM.bmWidth          ' if the pixel is not the transparent one         If (Pixel(1, x, y) <> Pixel(1, 1, 1)) And (Pixel(2, x, y) <> Pixel(2, 1, 1)) And (Pixel(3, x, y) <> Pixel(3, 1, 1)) Then ' Calculating the distance b/w the considered pixel and the center pixel                 Dis = Int(Math.Sqr((x - BM.bmWidth \ 2) * (x - BM.bmWidth \ 2) + (y - BM.bmHeight \ 2) * (y - BM.bmHeight \ 2)) * 256 \ (Max(BM.bmWidth, BM.bmHeight) \ 2))                 Alpha = Max(Min(255 - Dis, 255), 0) ' Finally setting the colour with its newly calculated Alpha                 Pixel(1, x, y) = ColBlue * Alpha \ 256                 Pixel(2, x, y) = ColGreen * Alpha \ 256                 Pixel(3, x, y) = ColRed * Alpha \ 256                 Pixel(4, x, y) = Alpha         Else                 Pixel(1, x, y) = Empty                 Pixel(2, x, y) = Empty                 Pixel(3, x, y) = Empty                 Pixel(4, x, y) = Empty         End If      Next x Next y Call SetDIBits(DC, DIB, 0, BM.bmHeight, Pixel(1, 1, 1), BIH, 0) ' Finally setting the Bits back.Its like refreshing the Memory End Sub Private Function Max(ByVal v1 As Long, ByVal v2 As Long) As Long   If v1 > v2 Then Max = v1 Else Max = v2 End Function Private Function Min(ByVal v1 As Long, ByVal v2 As Long) As Long   If v1 > v2 Then Min = v2 Else Min = v1 End Function Private Sub Form_Unload(Cancel As Integer) ' I believe the most important subroutine of all my projects is the Form_Unload.After all it can cause my system crash if not called Erase Pixel() CopyMemory lBlend, 0&, 4 Call SelectObject(DC, OldDIB) Call DeleteObject(DIB) Call DeleteDC(DC) End Sub

Its a simple program and I suppose well-commented so I'm not going to define it at all. Just one thing that anyone can fetch out another Graphic random algorithm of his own and put it here in this project. Its easy to do it. Another example of the random algorithm is the following routine. I just edited the Form_Load and Timer1_Timer subroutines. Now a flower will be drawn on the screen. Its quite beautiful..

' Personal Declarations Dim PI As Double, i As Long Dim Xangle As Long, Yangle As Long Dim Xspeed As Double, Yspeed As Double, Xradius As Double, Yradius As Double Dim Xrad As Double, Yrad As Double, nx As Long, ny As Long Private Sub Form_Load() Xspeed =  0.83 Yspeed =  0.52 Xradius = 200 Yradius = 200 PI = (4 * Atn(1)) / 180 End Sub Private Sub Timer1_Timer() Xspeed = xs.Value / 100 ' 0.83 Yspeed = ys.Value / 100 ' 0.52 Xangle = Xangle + Xspeed Yangle = Yangle + Yspeed Xradius = Xradius - 10 Yradius = Yradius - 10 If (Xradius = 0) Or (Yradius = 0) Then i = i + 0.5 Xradius = 200 + (i * 20) Yradius = 200 + (i * 20) End If Xrad = Xangle * PI Yrad = Yangle * PI nx = Math.Sin(Xrad) * Xradius + 400 ny = Math.Cos(Yrad) * Yradius + 300 '  here now AlphaBlend the picture to the calculated (nx,ny) End Sub