BGE Roller coaster
<img src="http://3dartdh.files.wordpress.com/2013/03/gif_bge-rollercoaster-blender-22.gif?w=400" alt="bge rollercoaster blender 2.66a" width="707" height="424" />
The roller coaster route can easily modified by deformation the curve in Edit Mode.
The wagons of the roller coaster are connected to an Armature , the Armature is moved in the Y direction by an Empty and the bones of the Armature are following the path of the curve.
I set the Inverse Kinematics of the Armature on iTaSC / Simulation, so the roller coaster adapts properly along the route (Object Data / Inverse Kinematics / iTaSC / Simulation)
Here is a short demo video:
I also used the setting for animate the train in this video:
I think this is the first real-time roller coaster in Blenders game engine, but I'm not sure.
Have fun with it :)
Roller coaster Controls:
Forward Speed: Right Mouse Button
Reverse Speed: Left Mouse Button