Ok the supplies you will need to create the heartlining effect, are as follow:
Two [2] peices of curved track
One [1] peice of straight track
Whatever method of support you use
To begin you will connect the curved track to the straight track so that [put together] they will look like a backwards L, in a way.
The next turn peice will be placed on the opposite end of the first peice in the opposite direction to appear as a strechted out Z.
When the peices are connected you simply create a roll. To do that you will twist the track in both directions. With the turns make both of the turn peices begin to curve up towards the end (inside of the roll), then the straight peice should begin to go up in the middle, then stretch out the track, without sacrificing the current position. You should now have a heartline roll. Now support where needed. The form of the roll should be easy to remember so you can most likley form it after you are ready to support it.
This same effect would work on a flying snake dive, there would only be one turn peice though. This would be turning to the direction that you want the roll to turn. If you want to see what this looks like a drop a comment and I will try to have it up soon...
This is a picture of a heartline roll on Prometheus
Enjoy!
