ray picking | GameDev.net

hi guys, I'm trying to check for intersections with meshes in my scene(to find out which tile the user clicked on). I am developing a fake isometric(ortho view) tile based game in c# and MDX. I found an example of how to do this in vb.net(intersecting teapot mesh). I played around with it in vb, added extra meshes and changed the view and projection matrices etc. just to mimic how I would be using it in my game. I can't however seem to get the ray picking to work now that I have converted the code. any ideas on where I could be going wrong? here is the vb ver


 Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        '=======Parameters
        presentParams = New PresentParameters
        presentParams.Windowed = True
        presentParams.SwapEffect = SwapEffect.Discard
        '=======Device
        dev = New Direct3D.Device(0, DeviceType.Hardware, pic3d, CreateFlags.HardwareVertexProcessing, presentParams)
        '=======Mesh
        mesh = mesh.Teapot(dev)
        mesh2 = mesh.Teapot(dev)

        '=======Camera
        dev.Transform.View = Matrix.LookAtLH(New Vector3(0.0F, 2.0F, 2.0F), New Vector3(0, 0, 0), New Vector3(0, 1, 0))
        'dev.Transform.View = Matrix.LookAtLH(New Vector3(0.0F, 30.0F, 30.0F), New Vector3(1, 1, 0), New Vector3(0, 1, 0))
        'dev.Transform.View = Matrix.LookAtLH(Me.Width / 35, Me.Height / 35, -1000.0F, 10000.0F)

        dev.Transform.Projection = Matrix.OrthoLH(CSng(Math.PI / 4), 1.3333, 1, 100)
        '=======Loop
        Me.Show()
        MainLoop()
    End Sub

    Private Sub MainLoop()
        Do
            Render()
            Application.DoEvents()
        Loop
    End Sub

    Private Sub Render()
        dev.Clear(ClearFlags.Target, System.Drawing.Color.CornflowerBlue, 1.0F, 0)
        dev.BeginScene()
        '==========
        vec1 = New Vector3(1.7, 0, 0)
        vec2 = New Vector3(-1.7, 0, 0)

        dev.Transform.World = Matrix.Translation(vec1)
        mesh.DrawSubset(0)


        dev.Transform.World = Matrix.Translation(vec2)
        mesh2.DrawSubset(0)
        '==========
        dev.EndScene()
        dev.Present()
    End Sub



    Private Sub Form1_Mousedown(ByVal sender As System.Object, ByVal e As _
    System.Windows.Forms.MouseEventArgs) Handles pic3d.MouseDown
        If e.Button = MouseButtons.Left Then
            Intersect(e.X, e.Y, vec1, mesh)
            Intersect(e.X, e.Y, vec2, mesh2)

        End If
    End Sub


    Public Sub Intersect(ByVal x As Single, ByVal y As Single, ByVal t As Vector3, ByVal m As Direct3D.Mesh)
        Dim Near As Vector3
        Dim Far As Vector3
        Dim Closest As IntersectInformation
        Dim locMesh As Mesh
        Dim tran As Vector3


        Near = New Vector3(x, y, 0)
        Far = New Vector3(x, y, 1)
        tran = New Vector3(0, 0, 0)

        locMesh = m


        Near.Unproject(dev.Viewport, dev.Transform.Projection, dev.Transform.View, Matrix.Translation(t))
        Far.Unproject(dev.Viewport, dev.Transform.Projection, dev.Transform.View, Matrix.Translation(t))
        Far.Subtract(Near)
        '=======================================================
        ' Here is where you check for an intersection
        If locMesh.Intersect(Near, Far, Closest) Then
            dev.RenderState.FillMode = FillMode.WireFrame

        Else
            'dev.RenderState.FillMode = FillMode.Solid
        End If




    End Sub

here is some important snippets from the c# ver


private void SetupCamera()
		{


			device.Transform.Projection = Matrix.OrthoLH(this.Width / 35, this.Height / 35,-1000.0f, 10000.0f);
			//device.Transform.View = Matrix.LookAtLH(new Vector3(0f,0f, 18.0f), new Vector3(28f,28f,0), new Vector3(1,1,0));
			device.Transform.View = Matrix.LookAtLH(new Vector3(0f,0f, 18.0f), new Vector3(28f,28f,0), new Vector3(1,1,0));

			//device.RenderState.Ambient = Color.DarkBlue;
			device.Lights[0].Type = LightType.Directional;
			device.Lights[0].Diffuse = Color.White;
			device.Lights[0].Direction = new Vector3(0, -1, -2);
			device.Lights[0].Enabled = true;

			
		}

protected override void OnMouseDown(MouseEventArgs e)
		{
			
			if(e.Button == MouseButtons.Left) 
			{

				intersection(grassMesh);

			 
			}
			
		}

private void intersection(StaticMesh staticMesh)
		{
			IntersectInformation closest = new IntersectInformation();

			Vector3 near = new Vector3(xMousePos,yMousePos,0);
			Vector3 far = new Vector3(xMousePos,yMousePos,1);


			Vector3 vec = (Vector3) tilesCoOrd[0];


			near.Unproject(device.Viewport,device.Transform.Projection,device.Transform.View,Matrix.Translation(vec));
			far.Unproject(device.Viewport,device.Transform.Projection,device.Transform.View,Matrix.Translation(vec));
			far.Subtract(near);


				Mesh mesh = staticMesh.getMesh();
				
				
				if(  mesh.Intersect(near,far,out closest))
				{
					
					//handle intersection
					

				}


		}

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