ο·―The trick to making this work depends primarily upon the alignment of the X Rotation. Mine is slightly more than 90 degrees. Once you are looking down the tunnel start to find your start and end positions. end positions. The movement through the tunnel is created by animating Z-Position. You will have to find a balance between Z-Position and Radius. So there will probably be a little going back and forth until you find the right combination. I added X and Y-Rotation for an enhancement to the motion. As the travel through the tunnel occurs the tunnel rotates .
You should have an image that looks something like this. Next Page Back