I am making a scene in Blender that involves a character walking into a diner. He simply opens the door, enters, and walks a few steps. However, the issue that I am facing is that I want the camera to start tracking the guy the moment he walks in. It may sound pretty simple, but I couldn't figure out how to have the camera follow the guy so that he's always in the center of the camera view. I don't want the camera to be static and rotate to the guy's direction, rather, I want it to move along as if it was on a track. The problem is that if I parent the camera to the rig, it will start following it and moving before the character reaches the middle of the screen (the camera is pointing at the door already).
As another possible solution, I created an empty which copies the rig movement and then added the Child Of constraint to the camera. I followed up by parenting the camera to the empty using this constraint and keyframing the influence so it kicks in when the guy is in the view center. It worked, but the camera snaps when the influence turns to 100%, so tweaked it a bit and Set Inverse many times until I had a shot where the camera follows the guy with no snapping, BUT it initiated the movement in a very linear way, I want the camera movement to start off smoothly, the interpolation modes did not solve the issue as the influence key frames are next to each other to eliminate the snapping issue.
Any thoughts on how to fix this?