have a look at this
when you move the mouse the cursor is supposed to move to wherever the ray(-Z axis) hits and there looks like a invisible plane that the ray hits
http://media2.uploadjar.com/file.php?file=uploads/untitled.blend
have a look at this
when you move the mouse the cursor is supposed to move to wherever the ray(-Z axis) hits and there looks like a invisible plane that the ray hits
http://media2.uploadjar.com/file.php?file=uploads/untitled.blend