Here's what I'd like to do, and I'm not quite sure where to begin... I'd like to have a 3D game object (let's say a primitive to keep things simple) that follows my cursor around. However I don't want it to simply stay perpendicular to the camera, I want it to ride along the top of a ground plane... imagine manipulating an air-hockey 'goalie' along the surface of a plane by moving your mouse. What I plan to have is a character that you direct by clicking the ground and having them walk to where you click. So it would be nice to have a 3d cursor of sorts that basically attaches itself to the ground wherever the mouse is floating over at any given time. My newbie assumption is that it would involve casting a ray out from the camera based on where the mouse is. From there it would be a simple matter of placing my cursor object at the point of impact between the raycast and the ground, but its the part leading up to that I can't get my head around. Any thoughts would be appreciated.