Get impact point problem //Help me please

[tikstt]

first of all I want to tell you about my project/
My project is Board game (Like chess) An I use TVmesh to my board by use

 Set board = New TVMesh
 Set board = Scene.CreateMeshBuilder

and I add floor by use(I create texture"BoardTexture" before this)

board.AddFloor GetTex("BoardTexture"), 0, 0, 160, 160, 0, 4, 4

next I want to check impact point when I click on board for move chess actor(3DS model)
by use

      If tmpMouseB1 <> 0 Then

        Set Pick = Scene.MousePicking(tmpMouseX, tmpMouseY, TV_COLLIDE_MESH, TV_TESTTYPE_BOUNDINGBOX)
       

        If Pick.IsCollision Then
       
        Picture1.Cls
        Picture2.Cls
        Picture3.Cls
        Picture1.Print Pick.GetImpactPoint.X
        Picture2.Print Pick.GetImpactPoint.Y
        Picture3.Print Pick.GetImpactPoint.Z
 
        End If

but I have some problem because I can't get true impact point

for example
          My  for board in world coordinate =
          (0,0,0)                          (0,0,160)
        (160,0,0)                        (160,0,160)
         Ummm...You can see  all Y=0 because it like plane
but when I check impact point(Y axis) on my board I get -186,150,-0.5,-16 and other

And next  I get false  X and Z too.
for example
         In neary point I get 500 and -800 but in real world is 500,499,498,497 ,and when I scan for check my impact point at X,Y,Z on board I can get about 0,150,-15,250,-80 not up from low to high

Um..Can you Help me? :cry:  :cry:  :cry:


What wrong in my code?
Can I use other object(ex. Landscape or Mesh) to be my board for get true impact point?
What is best object for my board?

could maybe take out bounding box and put accurate testing. i had weird results when using bounding box. (could have just been my models though  :? )