I have bitten the bullet and decided to have a go at writing a tile engine in D3D using Managed Direct 9 in VB.NET, I am using a single Vertex buffer for holding my tiles, a single texture file holds my textures. I am using a camera with 8 direction (pgup & pgdn to change ) viewing and 4 movement keys ( arrows keys ). I have set up a tile selector that uses W,A,S,D keys to move. I am still learning DirectX and this is my real first attempt at this. What I have done so far works, but I am now sorta stuck. Mouse click on screen to select tile????. I have searched and read all that I can about picking. It still doesn''t click with me yet. I am intending to add a zoom to the camera and allow height editing of the tiles also allowing the rotating of textures as well. If anyone can point me in the right direction about a mouse click on the screen translating through to a tile via intsecting a vertex buffer on the world space. All are welcome to grab what I have done so far. The project is at the site below (includes an executable ) note requires .NetFrame work. Grab it have a look, and if you can help me with the selector. http://homepages.infogen.net.nz/majathom/ Transworld.Zip is the file to grab. thanks