11 Replies Latest reply on Jul 30, 2008 10:52 PM by (didgi)

    Motion tracking question-2d or 3d tracker

      hi

      i'd like to put a 3d scallop model (c4d) on one of the coral in front of this video.
      it's video Vus 109.

      http://www.artbeats.com/collections/253

      Would you guys use a 2d or 3d tracker for this task?
      There is no zooming in this clip .
      thx for your time.
        • 1. Re: Motion tracking question-2d or 3d tracker
          Mylenium Most Valuable Participant
          Depends on what the clam is supposed to do, I guess. If it's just sitting there, it should be simple enough to use AE's 2D tracker and fix up a few kinks manually. If it's moving, then it may entail some more work. If you use C4D, this should be your starting point. You can easily export all motion using the composition export. If you have a 3D tracking program at hand, maybe at your company or a colleague, then sure, use it to your advantage, but otherwise this should not require too much hand-keyframing of the camera motion in C4D...

          Mylenium
          • 2. Re: Motion tracking question-2d or 3d tracker
            Level 1
            hi

            thx mylenium for your reply.
            the calm is just sitting there and will open.Then,words spread out of the shell
            and build up a DVD menu.That's the idea.
            Is it possible to use Ae's tracking data in C4D?
            THX
            • 3. Re: Motion tracking question-2d or 3d tracker
              Mylenium Most Valuable Participant
              There's some scripts floating around at AEnhancers, mainly for returning the AE camera back to C4D. Maybe you can find some use for that. There's also some scripts for generating Lightwave scenes and since C4D imports them correctly, this should also work.

              Mylenium
              • 4. Re: Motion tracking question-2d or 3d tracker
                Level 1
                Hi

                I've found the script.
                http://www.aenhancers.com/viewtopic.php?f=9&t=653&st=0&sk=t&sd=a&start=0

                i folowed the instructions:
                1. Put pt_AEtoC4D.jsx in Adobe After Effects / Scripts

                2. Put pt_AEtoC4D.CSC in Cinema 4D / library / scripts.

                3. Animate your scene in After Effects using a Camera with Layer >
                Transform > Auto-Orient set to Off. Animate rotation using the XYZ
                Rotation properties, not Orientation.

                4. Select the cameras and layers you want to export and choose File >
                Scripts > pt_AEtoC4D.jsx. You'll be prompted to save a text file.

                5. In C4D, select Plugins > User Scripts > pt_AEtoC4D and select
                that text file.

                The only thing that does not work is point 5.In C4d under> Plugins > User Scripts
                nothing shows up.WHY?
                Any ideas?

                THX
                • 5. Re: Motion tracking question-2d or 3d tracker
                  Level 1
                  hi

                  >There's also some scripts for generating Lightwave scenes and since C4D imports them correctly,

                  I've tried to import the lightwave scene and it showed up but the position keyframes don't match.Has anybody experiences with this task and is willing to share with me?
                  What do i need to take care of in c4d and ae????
                  • 6. Re: Motion tracking question-2d or 3d tracker
                    Level 1
                    Hi

                    I've got some problems with tracking the above mentioned footage.
                    The tracker remains pretty well on the target object.When i apply this data to a solid for example,the solid is jumping slightly up and down throughout the shot.It's obviously not a perfect track.
                    is there any way to reduce this bumpiness?Smaller Feature/search region?
                    Thx
                    • 7. Re: Motion tracking question-2d or 3d tracker
                      Level 1
                      Actually, you want to use a larger feature if you're getting some vibration, which will help even out the errors.

                      The fact is, AE's tracker is pretty basic, and for a complex track like this, you may need to do a LOT of manual tweaking.

                      You might want to consider investing in a dedicated tracking station. I use Mocha-AE with usually excellent results.
                      • 8. Re: Motion tracking question-2d or 3d tracker
                        Mylenium Most Valuable Participant
                        As pointed out, use larger feature regions and search areas. You can also even out bumps by using the Smoother palette or respective expressions with the .smooth() method. Investing in better tools is certainly no bad idea, but seems a bit too much for just one such simple task.

                        Mylenium
                        • 9. Re: Motion tracking question-2d or 3d tracker
                          Level 1
                          Hi

                          Thanks for your replies.
                          Have a look at this sample clip.
                          http://www.zshare.net/video/1597190539330799/
                          The red solid has got ae' s tracking data.
                          I exported this solid from AE to C4d.In C4d i parented a 3d model to this solid=>export
                          Targa Seq.of 3d model.

                          In AE i reimport the targa seq.=>composite over real footage.
                          Why is there such a big difference in motion???
                          • 10. Re: Motion tracking question-2d or 3d tracker
                            Level 1
                            Hmmm... well you managed to pull a quite decent track in AE.

                            About the discrepancy: It may be a mismatch with framerate or interlacing. If your source footage is interlaced but your render is progressive it could create this kind of error. Otherwise, it's not on the AE side. I'm sure folks with C4d experience will be very useful in that case.

                            What I can suggest, is to try not to do the motion tracking and parenting in C4D. Can you use the solid's position to drive rotation only (that is, perspective change)?

                            If so, render out your rotating scallop shell, and parent it to the solid in AE.
                            • 11. Re: Motion tracking question-2d or 3d tracker
                              Level 1
                              Hi

                              i About the discrepancy: It may be a mismatch with framerate or interlacing.

                              Yes,it seems that when i render with 30fps instead of 29fps in C4d,it works.It's a C4d issue.
                              29.97fps doesn't exist in C4d export settings.

                              THX