15 Replies Latest reply on Sep 4, 2013 1:38 AM by Pierre Devereux

    Tracking markers for flight scenes

    Pierre Devereux Level 2

      Hi,

       

      Just a shot in the dark here - does anyone have some advice for tracking markers that we can use for tracking engines on our scaled models?

       

      Since we are not using 3D apps, I have to track while shooting somehow. I did try somethings:

       

      1) Created a square "dice" with a checker patter on it.

      2) Attached to blue poles

      3) Attached to ship

      4) tracked

       

      The problem with this, is the rate of movement of the tracer markers obviously doesnt match the actual engine - so the results were terrible.

       

      Has anyone here had successfull experience with tracking markers for planes? any suggestions would be appreciated.

       

      Here is a screenshot of the rig I first tested:

       

      Ship.JPG

       

      I am now going to try and find a way to attach the markers connecting horizontally to the engine, so they stay on the same plane.

       

      Thank you

       

      Pierre

        • 1. Re: Tracking markers for flight scenes
          Dave LaRonde Level 6

          How about trying AE's 3D tracker?  You may not even need dice & poles.

          • 2. Re: Tracking markers for flight scenes
            Pierre Devereux Level 2

            Hi Dave,

             

            Nice to hear from you - I hope all is well?

             

            Thank you for the advice, I must admit, I have read so many articles stating that the camera can only "do so much" that I think I made a dangerous assumption on the trackers behalf and decided it wont work!

             

            After that, I kind of forgot about the tracker alltogether.

             

            Thanks for reminding me about it, I will test it this morning first thing. Ill post an update here later today.

             

            Pierre

            • 3. Re: Tracking markers for flight scenes
              Rick Gerard Adobe Community Professional & MVP

              I'm not sure what kind of motion you are trying to track but it has been my experience that most of these kind of shots are best tracked in Mocha as planes and then corner pin data is used to bring in the effect. If we knew more about the motion of the ship then maybe we would have some better ideas. Is it just flying past the camera or does it turn or is the camera moving around the ship? Inquiring minds want to know.

               

              There's a tutorial by Andrew Kramer in a post I just replied to that shows how he uses Mocha to track a face turning. The very same technique could be used to track the movement of your ship and line up whatever you want. I'd suggest you take a look at it.

               

              If you need 3D tracking to add 3D elements then I'd suggest some 3D tracking. Here again, markers are usually not needed. The only time I ever add markers is when the object being tracked has no discernable detail.

               

              Another option would be to stabilize the shot so the ship does not move by using AE or Mocha to track the ship and lock it in the frame. You then add your effect and then re-introduce the motion using parenting and a null. Here's the technique in a quick video (sorry no audio. I did the screencast in a coffee shop the other day). You could use the technique to add the rocket blast to your engines in the same way that I added a target that tracked the girl in the marching band.

               

              • 4. Re: Tracking markers for flight scenes
                Pierre Devereux Level 2

                Hi Rick,

                 

                Thank you for the info. I am going to go next door to take some stills to post, but the run down is as follows:

                 

                We have several rigs, and several ships that we want to attach engine glows to. The rigs either rotate on one axis, or are completely free moving (as said, aIll get some descriptive stills in a bit). Each ship has several points to attach to the rigs, depending on what shot we want.

                 

                My biggest hope, was that I could use the markers to track the engine that would be "out of shot".

                 

                On the camera side, we either place the camera on a tripod and move the ship, or we sometimes place the camera on a dolly and move past the ship. To make it even more fun, sometimes we place both the ship and the camera on a dolly to get some large nice movement.

                 

                I did not think the tracking markers through properly on the first attempt, and ignored the physics, so as the engine moved away from the camera, the marker came closer! what a mess!

                 

                Anyway, I will go get the pictures now and post them in a bit. I will try to get as many of our different set ups as possible, just for some advice. I am also busy transcoding some footage from yesterday to test the 3D camera while I am away.

                 

                Thank you

                 

                Pierre

                • 5. Re: Tracking markers for flight scenes
                  Pierre Devereux Level 2

                  Hi,

                   

                  Before I post the stills - Dave,

                   

                  Thank you so much for the suggestion! I tracked 3D camera and where as it migfht not be 100%, it is 99% perfect! - there are one or two spotsw where it drifts a bit, but otherwise it is really really great.

                   

                  I have the footage, I am going to pull some still now and post them, then do some further tests with the poles and the 3D camera - this is great stuff!

                   

                  Pierre

                  • 6. Re: Tracking markers for flight scenes
                    Pierre Devereux Level 2

                    Hi,

                     

                    Here are some really low res stills for the rig I am currently testing. It only moves/rotates on one axis. The ship is mounted by one of two points, and the camera is attached to a tripod on the ground. No dolly movements in these specific shots:

                     

                    Rig at ease - ship from the front:

                     

                    01.JPG

                     

                    Ship starting a roll:

                     

                    02.JPG

                     

                    Ship continuing roll:

                     

                    03.JPG

                     

                    Rig at ease from the side:

                     

                    04.JPG

                     

                    Ship starting roll:

                     

                    05.JPG

                     

                    Ship continuing roll:

                     

                    06.JPG

                     

                    Obviously I have not lit the screens for keying, I am only interested in tracking for now.

                     

                    Thanks guys.

                     

                    Pierre

                    • 7. Re: Tracking markers for flight scenes
                      Pierre Devereux Level 2

                      I am going to run this footage through the 3D camera and Mocha, and probably AE point tracker as well to see what works best.

                       

                      Then Ill probably have to do these tests for each scenario and rig.

                       

                      Cheers

                       

                      Pierre

                      • 8. Re: Tracking markers for flight scenes
                        Pierre Devereux Level 2

                        Hi,

                         

                        After several tests, I am trying again at a slightly faster shutter speed (to reduce blur) and better lighting!

                         

                        I see that the tracking markers I have had designed will not work at all. The physics just dont match up.

                         

                        The second three shots above - from the side - the markers have to be exactly in line with where the engines are, or the tracking will travel badly - I guess it is easier than a manual track, but there are quite a few keyframe changes.

                         

                        The first three, well, they have the same issue I had yesterday - the turning circle on the markers is much larger than the turning circle of the engines they are attached to - so the null doesnt work very well at all. I am currently re testing Dave's 3D camera tracker on the new footage. It worked well on my original footage, then rather badly on the footage that the stills above were taken off. I have re-shot, and will advise once done.

                         

                        Pierre

                        • 9. Re: Tracking markers for flight scenes
                          Rick Gerard Adobe Community Professional & MVP

                          You have to track the planes you want to attach things to. That's a fact. I should have mentioned that in my first post. Unfortunately one technique will not work for all situations. To make things easier in post I'd think about attaching LED's embedded in the engine nacelles. They could light up the back of the engine and provide good tracking information any kind of plainer or point tracking. BTW, AE's point tracker is really an area tracker and works best if you track a fairly large area that doesn't change shape much. See my sample movie.

                          • 10. Re: Tracking markers for flight scenes
                            Pierre Devereux Level 2

                            Hi Rick,

                             

                            Yeah, I have had some success with Dave's 3D camera suggestion, and some failures too! So I see that I will need to build up a good "Tracking Toolbox" of different techniques, and start to learn to "Best Guess" which technique will work for which shot.

                             

                            I must admit, that I am having quite a bit of success with your stabalize/destabalize method, both for head on, and side to side shots. There are just a few areas, when the tracking point goes behind another area of the ship, where a few keyframe changes are needed, otherwise, it is not too bad at all. For simple one axis moves, that this rig allows, I think this will be the tracking method going forward.

                             

                            Ill do some tests on another rig tomorrow.

                             

                            Thanks for the advice guys,

                             

                            Pierre

                            • 11. Re: Tracking markers for flight scenes
                              Fuzzy Barsik Level 4

                              I second Rick on embedding LED lights into the engine's nozzles.

                              • 12. Re: Tracking markers for flight scenes
                                Pierre Devereux Level 2

                                Hi Guys,

                                 

                                Ok, I would like to try placing LED lights into the  engine nacelles (and yes, even though I had a pretty good idea what that was Rick, I still looked it up on Google to be sure! )

                                 

                                2 questions about it though:

                                 

                                1) Should they be a specific colour, or rather white

                                2) Should the be completely inside the Nacelle, or should they protrude slightly,

                                 

                                and 3) yes...um, 3 questions (no-one expects the spanish inquisition....)

                                 

                                3) What brightness are we looking at - (the space for these lights is rather small, so I am wondering what typoe of LED is suggested.

                                 

                                Thank you

                                 

                                Pierre

                                • 13. Re: Tracking markers for flight scenes
                                  Pierre Devereux Level 2

                                  Hi,

                                   

                                  I am still playing around with the 3D camera tracker, but having some hassles. With the set up above, doing a barrel-roll from the side, two revolutions, the 3D camera is able to resolve the first half of the clip, but fails on the second half - same movement, same lighting same shoot. I also see that it has difficulty resolving, as the tracks slide here and there, and the initial resolve, the track points are really really small.

                                   

                                  Any suggestions on things I should be looking for to make the tracking a bit better? I am aware that certain shots just wont work, I just want to exhaust all the possibilities.

                                   

                                  Thank you

                                   

                                  Pierre

                                  • 14. Re: Tracking markers for flight scenes
                                    Fuzzy Barsik Level 4

                                    As for me, since LED lights' only purpose is to serve as tracking markers, the colour is not crucial.

                                     

                                    The closer you can attach them to the target, the better. However, mind 'satisfactory decision': if I'm not mistaken, you're a couple of days prior to start of production, hence you hardly have time to rebuild your space fleet from scratch.

                                     

                                    Light shouldn't be too bright so as not to cause light trails while shooting and, therefore, make it impossible to track in post.

                                    • 15. Re: Tracking markers for flight scenes
                                      Pierre Devereux Level 2

                                      Thanks Fuzzy!

                                       

                                      Yup, after almost 2 years, we are "hopefully" just a week or so from starting. What a journey its been so far!

                                       

                                      I shudder to even imagine rebuilding the space fleet.

                                       

                                      ill run some tests today and give feedback.

                                       

                                      Pierre