The entire roller coaster or just the tracks? It's a lot of work! How well do you know CATIA? Do you know how to use CATIA Laws?
A couple years ago, I helped another guy with some questions about the track. He posted a couple videos on You Tube. Here's one: https://www.youtube.com/watch?v=yMV2TVu_M5E
Hi I just need a simple track drawing. I attempted it myself but failed miserably. Just a coaster track that starts on a hill and goes into a inverted loop.
You said "drawing" in your last post; do you just want a 2D drawing, or a 3D Model?
For a 3D model: First thing you will need is a sketch of the top view (plan view) of the track (centerline only). (don't worry about the loop details - just the start and end point of the loop will be okay for now)