Hi all. My English is poor, so please bare with me :) I'm fooling around with landscape generation. So far so good, until I hit the Voroni diagram... For simplicity purpose, I generated a diagram without any equation and it seems to work properly (left image). However, the pseudocode I found here gives me a weird result (right image). On Left: distanceBuffer(x, y) = nearestDistance On right: distanceBuffer(x, y) = nearestDistance2 - nearestDistance But there is something that bothers me in this:

If nearestDistance < minimumDistance Then minimumDistance = nearestDistance
If nearestDistance > maximumDistance Then maximumDistance = nearestDistance

For x As Integer = 0 To tableSizeX
    For y As Integer = 0 To tableSizeY
        pixel(x, y) = (distanceBuffer(x, y) - minimumDistance) / (maximumDistance - minimumDistance)
    Next
Next

If I'm using 2 distances, how come I'm only using minimum and maximum distance from distance #1? Here's the whole thing (yes, it's in VB.net, sorry, I'm a hobbyist and know no other languages for now... working on it):

Private Sub GenerateVoronoi()

    ' Generate Voronoi
    If voronoiPoints = 0 Then

        ' No voroni cells to generate, just copy from perlin table
        voronoiTable = perlinTable

    Else

        ' Create at least 1 Voroni cell
        Dim numPoints As Integer = voronoiPoints - 1

        ' Okay, this is going to be crazy fun... 
        Dim distanceBuffer(bufferSizeX, bufferSizeY) As Single
        Dim positionX(numPoints) As Single
        Dim positionY(numPoints) As Single
        Dim minimumDistance As Single = Single.MaxValue
        Dim maximumDistance As Single = 0

        ' Randomly fill the buffer
        For i As Integer = 0 To numPoints
            positionX(i) = Rnd() * bufferSizeX
            positionY(i) = Rnd() * bufferSizeY
        Next

        ' Get distance for every pixel
        For x As Integer = 0 To bufferSizeX
            For y As Integer = 0 To bufferSizeY

                ' Find nearest point
                Dim nearestDistance As Single = Single.MaxValue
                Dim nearestDistance2 As Single = Single.MaxValue
                For i As Integer = 0 To numPoints

                    ' Get distance for this point
                    Dim point1 As New MTV3D65.TV_2DVECTOR(x, y)
                    Dim point2 As New MTV3D65.TV_2DVECTOR(positionX(i), positionY(i))
                    Dim distance As Single = CoreGlobal.GetDistance2D(point1, point2)

                    ' Set nearest distance
                    If distance < nearestDistance Then
                        nearestDistance = distance
                    ElseIf distance < nearestDistance2 Then
                        nearestDistance2 = distance
                    End If

                Next

                ' Set distance table
                Select Case voronoiGeneration
                    Case EnumVoronoi.Normal

                        ' Set distance
                        distanceBuffer(x, y) = nearestDistance

                        ' Check distance from nearest point
                        If nearestDistance < minimumDistance Then minimumDistance = nearestDistance
                        If nearestDistance > maximumDistance Then maximumDistance = nearestDistance

                    Case EnumVoronoi.Negative

                        ' Set distance
                        distanceBuffer(x, y) = nearestDistance2 - nearestDistance

                        ' Check distance from nearest point
                        If nearestDistance < minimumDistance Then minimumDistance = nearestDistance
                        If nearestDistance > maximumDistance Then maximumDistance = nearestDistance

                    Case EnumVoronoi.Multiplied

                        ' Set distance
                        distanceBuffer(x, y) = nearestDistance * nearestDistance2

                        ' Check distance from nearest point
                        If nearestDistance < minimumDistance Then minimumDistance = nearestDistance
                        If nearestDistance > maximumDistance Then maximumDistance = nearestDistance

                End Select

            Next
        Next

        ' Set table
        For x As Integer = 0 To bufferSizeX
            For y As Integer = 0 To bufferSizeY
                voronoiTable(x, y) = (distanceBuffer(x, y) - minimumDistance) / (maximumDistance - minimumDistance)
            Next
        Next

    End If

End Sub

[Edited by - vracicot on July 5, 2008 8:34:52 PM]

Quote:Original post by dmatter
In point of fact, wouldn't that whole thing be better off like this:

er... yes, makes more sense!

but still doesn't fix my problem of trying to reproduce this:



but I'm only able to get this:

Quote:Original post by dmatter
Are you using the exact same data sets and same random number seed?

Well dmatter, that was a part of it! There was also a redundance in my loop which made some values go under 0... So silly of me. Thanks a bunch for pointing me out :)




And, of course, the code for people who will be looking at this thread in the future:

    Private Sub GenerateVoronoi()        ' Generate Voronoi        If voronoiPoints = 0 Then            ' No cells to generate            voronoiTable = perlinTable        Else            ' Create at least 1 cell            Dim numPoints As Integer = voronoiPoints - 1            ' Okay, this is going to be crazy fun... :s            Dim distanceBuffer(tableSizeX, tableSizeY) As Single            Dim distanceFromCenter(numPoints) As Single            Dim positionX(numPoints) As Single            Dim positionY(numPoints) As Single            Dim minimumDistance As Single            Dim maximumDistance As Single            Dim minimumDistanceTotal As Single = Single.MaxValue            Dim maximumDistanceTotal As Single = Single.MinValue            ' Set cells            For i As Integer = 0 To numPoints                ' Randomly fill the cells                positionX(i) = Rnd() * tableSizeX                positionY(i) = Rnd() * tableSizeY                ' Get distance from middle of table                Dim point1 As New MTV3D65.TV_2DVECTOR(positionX(i), positionY(i))                Dim point2 As New MTV3D65.TV_2DVECTOR(tableSizeX * 0.5!, tableSizeY * 0.5!)                distanceFromCenter(i) = CoreGlobal.GetDistance2D(point1, point2)            Next            ' Get distance for every pixel            For x As Integer = 0 To tableSizeX                For y As Integer = 0 To tableSizeY                    ' Reset                    minimumDistance = Single.MaxValue                    maximumDistance = Single.MinValue                    ' Find nearest point                    For i As Integer = 0 To numPoints                        ' Get distance for this point                        Dim point1 As New MTV3D65.TV_2DVECTOR(x, y)                        Dim point2 As New MTV3D65.TV_2DVECTOR(positionX(i), positionY(i))                        Dim distance As Single = CoreGlobal.GetDistance2D(point1, point2)                        ' Set nearest distance                        If distance < minimumDistance Then                            maximumDistance = minimumDistance                            minimumDistance = distance                        ElseIf distance < maximumDistance Then                            maximumDistance = distance                        End If                    Next                    ' Set distance table                    Select Case voronoiGeneration                        Case EnumVoronoi.Normal : distanceBuffer(x, y) = minimumDistance                        Case EnumVoronoi.Negative : distanceBuffer(x, y) = maximumDistance - minimumDistance                        Case EnumVoronoi.Multiplied : distanceBuffer(x, y) = maximumDistance * minimumDistance                    End Select                    ' Check distance from nearest point                    If distanceBuffer(x, y) < minimumDistanceTotal Then                        minimumDistanceTotal = distanceBuffer(x, y)                    ElseIf distanceBuffer(x, y) > maximumDistanceTotal Then                        maximumDistanceTotal = distanceBuffer(x, y)                    End If                Next            Next            ' Reset            minimumDistance = Single.MaxValue            maximumDistance = Single.MinValue            ' Check distance from center            For i As Integer = 0 To numPoints                If distanceFromCenter(i) < minimumDistance Then                    minimumDistance = distanceFromCenter(i)                ElseIf distanceFromCenter(i) > maximumDistance Then                    maximumDistance = distanceFromCenter(i)                End If            Next            ' Set table            For x As Integer = 0 To tableSizeX                For y As Integer = 0 To tableSizeY                    voronoiTable(x, y) = (distanceBuffer(x, y) - minimumDistanceTotal) / (maximumDistanceTotal - minimumDistanceTotal)                Next            Next            ' Normalize 0..1            voronoiTable = NormalizeTable(voronoiTable)            ' Check inverted colors            If voronoiInverted Then                For x As Integer = 0 To tableSizeX                    For y As Integer = 0 To tableSizeY                        voronoiTable(x, y) = 1 - voronoiTable(x, y)                    Next                Next            End If            ' Concatenate tables            For x As Integer = 0 To tableSizeX                For y As Integer = 0 To tableSizeY                    ' Lerp between the two tables                    voronoiPerlinTable(x, y) = CoreGlobal.LinearLERP(perlinTable(x, y), _                                                                     voronoiTable(x, y), _                                                                     voronoiPresence)                Next            Next        End If    End Sub