Hi All, I have been thinking about creating a user interface for a while - just the basics of windows, images and buttons. I have done this with DX7 and surfaces, but I was wanting to try one in DX8 and 3D, incorporating alpha and the like. I can get the look I want, but my problem is in getting user feedback. For instance : If I store each control as a simple mesh and shoot a ray from the mouse position, I can see if the ray intersects the mesh, but is there a way to determine whether the ray intersects a part of the mesh is not transparent? Meshes do seem like a bit of overkill for each control - I have a sprite class that I wrote which could do the job (with triangle lists), but I come up against the same issue (plus my triangle intersection math is somewhat poor - but I can look that up). I just would like a pointer in the right direction of how to take a point of intersection on geometry to get the textures pixel properties. Thanks for any help, Steele.