Drawing objects

T

theHollow

Newcomer
Joined
Jan 4, 2005
Messages
9
Hi there!
This may to many of you seem like a stupid question. But my objects seem to be transparent to the objects to the right. I must have misunderstood something here. I'm using VB.NET, and I'm using PositionNormalColored() to create the triangles.

I use DirectX9c dec.04 and the DirectX object is named D3Ddev in this program. I use no lights (so far). I would very much appreciate if someone could tell me why the cubes to the right "shines through" the ones to the left.

Do I create the triangles the wrong way? Like counter clockwise instead of clockwise? I really have no idea at all. I have programmed "normal" applications for quite a while, but I am very(!) new to DirectX programming.

Here is some code (not complete...too much to post :-\ ):

Visual Basic: 
' Some variables I use
Private buffer(5) As VertexBuffer
Private vertex(5) As Integer
Private numObj As Integer
Visual Basic: 
'---------------------'
' CREATING THE CUBE '
'---------------------'
' This function returns the number of vertices that is used in this object
Private Function CreateCube(ByRef aBuffer As VertexBuffer, ByVal posX As Single, ByVal posY As Single, ByVal posZ As Single, ByVal x As Single, ByVal y As Single, ByVal z As Single, ByVal col As Integer) As Integer
        Dim Vertices() As CustomVertex.PositionNormalColored
        Const antVertices = 36

        aBuffer = New VertexBuffer(GetType(CustomVertex.PositionNormalColored), antVertices, D3Ddev, Usage.WriteOnly, CustomVertex.PositionNormalColored.Format, Pool.Default)
        Vertices = aBuffer.Lock(0, LockFlags.None)

        ' Front face
        Vertices(0) = New CustomVertex.PositionNormalColored(New Vector3(posX, posY + y, posZ), New Vector3(0.0F, 0.0F, -1.0F), col)
        Vertices(1) = New CustomVertex.PositionNormalColored(New Vector3(posX + x, posY + y, posZ), New Vector3(0.0F, 0.0F, -1.0F), col)
        Vertices(2) = New CustomVertex.PositionNormalColored(New Vector3(posX, posY, posZ), New Vector3(0.0F, 0.0F, -1.0F), col)
        Vertices(3) = Vertices(1)
        Vertices(4) = New CustomVertex.PositionNormalColored(New Vector3(posX + x, posY, posZ), New Vector3(0.0F, 0.0F, -1.0F), col)
        Vertices(5) = Vertices(2)

        ' Back face
        Vertices(6) = New CustomVertex.PositionNormalColored(New Vector3(posX + x, posY + y, posZ + z), New Vector3(0.0F, 0.0F, 1.0F), col)
        Vertices(7) = New CustomVertex.PositionNormalColored(New Vector3(posX, posY + y, posZ + z), New Vector3(0.0F, 0.0F, 1.0F), col)
        Vertices(8) = New CustomVertex.PositionNormalColored(New Vector3(posX + x, posY, posZ + z), New Vector3(0.0F, 0.0F, 1.0F), col)
        Vertices(9) = Vertices(7)
        Vertices(10) = New CustomVertex.PositionNormalColored(New Vector3(posX, posY, posZ + z), New Vector3(0.0F, 0.0F, 1.0F), col)
        Vertices(11) = Vertices(8)

        ' Left face
        Vertices(12) = New CustomVertex.PositionNormalColored(New Vector3(posX, posY + y, posZ + z), New Vector3(-1.0F, 0.0F, 0.0F), col)
        Vertices(13) = New CustomVertex.PositionNormalColored(New Vector3(posX, posY + y, posZ), New Vector3(-1.0F, 0.0F, 0.0F), col)
        Vertices(14) = New CustomVertex.PositionNormalColored(New Vector3(posX, posY, posZ + z), New Vector3(-1.0F, 0.0F, 0.0F), col)
        Vertices(15) = Vertices(13)
        Vertices(16) = New CustomVertex.PositionNormalColored(New Vector3(posX, posY, posZ), New Vector3(-1.0F, 0.0F, 0.0F), col)
        Vertices(17) = Vertices(14)

        ' Right face
        Vertices(18) = New CustomVertex.PositionNormalColored(New Vector3(posX + x, posY + y, posZ), New Vector3(1.0F, 0.0F, 0.0F), col)
        Vertices(19) = New CustomVertex.PositionNormalColored(New Vector3(posX + x, posY + y, posZ + z), New Vector3(1.0F, 0.0F, 0.0F), col)
        Vertices(20) = New CustomVertex.PositionNormalColored(New Vector3(posX + x, posY, posZ), New Vector3(1.0F, 0.0F, 0.0F), col)
        Vertices(21) = Vertices(19)
        Vertices(22) = New CustomVertex.PositionNormalColored(New Vector3(posX + x, posY, posZ + z), New Vector3(1.0F, 0.0F, 0.0F), col)
        Vertices(23) = Vertices(20)

        ' Bottom face
        Vertices(24) = New CustomVertex.PositionNormalColored(New Vector3(posX, posY, posZ), New Vector3(0.0F, -1.0F, 0.0F), col)
        Vertices(25) = New CustomVertex.PositionNormalColored(New Vector3(posX + x, posY, posZ), New Vector3(0.0F, -1.0F, 0.0F), col)
        Vertices(26) = New CustomVertex.PositionNormalColored(New Vector3(posX, posY, posZ + z), New Vector3(0.0F, -1.0F, 0.0F), col)
        Vertices(27) = Vertices(25)
        Vertices(28) = New CustomVertex.PositionNormalColored(New Vector3(posX + x, posY, posZ + z), New Vector3(0.0F, -1.0F, 0.0F), col)
        Vertices(29) = Vertices(26)

        ' Top face
        Vertices(30) = New CustomVertex.PositionNormalColored(New Vector3(posX, posY + y, posZ + z), New Vector3(0.0F, 1.0F, 0.0F), col)
        Vertices(31) = New CustomVertex.PositionNormalColored(New Vector3(posX + x, posY + y, posZ + z), New Vector3(0.0F, 1.0F, 0.0F), col)
        Vertices(32) = New CustomVertex.PositionNormalColored(New Vector3(posX, posY + y, posZ), New Vector3(0.0F, 1.0F, 0.0F), col)
        Vertices(33) = Vertices(31)
        Vertices(34) = New CustomVertex.PositionNormalColored(New Vector3(posX + x, posY + y, posZ), New Vector3(0.0F, 1.0F, 0.0F), col)
        Vertices(35) = Vertices(32)

        'aBuffer.SetData(Vertices, 0, LockFlags.None)
        aBuffer.Unlock()

        CreateCube = antVertices
    End Function
Visual Basic: 
' Drawing the objects (this goes on a loop)
numObj = 3
vertex(0) = CreateCube(buffer(0), -0.5F, 0.0F, 0.0F, 0.5F, 0.5F, 0.5F, Color.Red.ToArgb)
vertex(1) = CreateCube(buffer(1), 0.0F, 0.0F, 0.0F, 0.5F, 0.5F, 0.5F, Color.Yellow.ToArgb)
vertex(2) = CreateCube(buffer(2), 0.5F, 0.0F, 0.0F, 0.5F, 0.5F, 0.5F, Color.Yellow.ToArgb)

D3Ddev.Clear(ClearFlags.Target, Color.FromArgb(255, 255, 255), 0, 0)
D3Ddev.BeginScene()

D3Ddev.Transform.View = Matrix.LookAtLH(New Vector3(0.0F, 0.0F, -3.0F), New Vector3(0.0F, 0.0F, 0.0F), New Vector3(0.0F, 1.0F, 0.0F))
D3Ddev.Transform.Projection = Matrix.PerspectiveFovLH(Math.PI / 3.0F, 1.0F, 1.0F, 10.0F)

' Drawing the number of objects that is set in numObj
For i = 0 To numObj - 1
  D3Ddev.SetStreamSource(0, buffer(i), 0)
  D3Ddev.DrawPrimitives(PrimitiveType.TriangleList, 0, vertex(i) / 3)
Next

D3Ddev.EndScene()
D3Ddev.Present()

Any tips, hints would be appreciated!

//theHollow
 
I haven't had the time to check all the vertices yet, but plot them on a peice of paper and be sure you're drawing the triangles in teh cube clockwise.

Turn off Culling if you don't feel like doing that. (I beleive its' d3ddev.renderstate.cullmode = cullmode.none).

Also, if that doesn't work, a screenshot might help :).

-The Pentium Guy
 
Back
Top