6 Replies Latest reply on Apr 30, 2014 7:24 PM by Cyber.Knight

    Boxcar Path

    Cyber.Knight

      I am using AE CS4 to have a train go down a winding path (engine, 16 boxcars, and a caboose). I assigned the path (masK) to the engine then linking the cars and caboose but that didn't work. Also tried doing a time delay. Any other methods?

       

      Thanks for any help.

        • 1. Re: Boxcar Path
          Mylenium Most Valuable Participant

          Well, that's a bit vague, don't you think? You need to explain much better and provide screenshots.

           

          Mylenium

          • 2. Re: Boxcar Path
            Cyber.Knight Level 1

            Sorry was in a hurry when I made that post. I will try to explain it better.

             

            I am having a train winding across the project (serpentine pattern). I have the train engine, followed by 16 boxcars, and completed with a caboose. I am using a mask path for the serpentine tracks. I originally copied the path to the position on each object, but they of course just piled on top of each other. Then I moved the keyframes for a time delay, that ended in the cars being out of sync in some places. Then I tried parenting the cars to the engine or a null object, that made the train turn into a board when taking turns. I am trying to avoid spending time keyframing each object. I did a search for ae chain paths and variances of that search. The closest thing that came back was somebody using echo and looping, which is not what i am trying to do. I hope this clears things up a bit. I probably will check back in around the same time tomorrow after work.

             

            Thanks for the response BTW

            • 3. Re: Boxcar Path
              Mylenium Most Valuable Participant

              Won't work. Unless the velocity is constant all the time, neither method would give a correct result and the spacing of the cars vary over time. Even a simple valueAtTime() expression doesn't resolve this. It's actually quite logical when you think about it: If one of the carts is on a cusp, the engine may already be in the valley, yet when the cart reaches the valley, it would have a different velocity from the engine when it was in this position, because it already climbs up on the other side. Basically what you would wnat is to offset the resulting velocity, not the actual coordinates. Short of buying Newton or creating a complex set of expressions I can't really think of that much besides keyframing. This is one of those typical examples where a align to spline/ spline deformer as they are common in 3D programs would be more than handy...

               

              Mylenium

              • 4. Re: Boxcar Path
                Rick Gerard Adobe Community Professional & MVP

                If the solutions from this great page from Dan Ebberts don't work, post a screenshot.

                 

                http://motionscript.com/mastering-expressions/follow-the-leader.html

                 

                Have you tried time remapping?

                • 5. Re: Boxcar Path
                  Cyber.Knight Level 1

                  I was experimenting by copying the path to each layer and adjusting the starting and end positions. It was close but not quite.

                   

                  I will try the expressions to see how it will work.

                   

                  Thanks

                  • 6. Re: Boxcar Path
                    Cyber.Knight Level 1

                    Found this video on youtube that is based off of what you suggested.

                     

                    https://www.youtube.com/watch?v=5RA3s2Kt98Y