10 Replies Latest reply on Jun 20, 2013 12:29 PM by Rick Gerard

    Multiple 3D Tracked Objects

    Lone Lobo Level 1

      I'm new to After Effects and struggling just a bit.  I tried searching this forum but found no obvious reference to my question.  I have figured out how 3d Tracking works for a single object, but don't know how to handle multiple tracked objects on the same video clip.  How do I go about tracking more than one object or Text Object in the same clip?

        • 1. Re: Multiple 3D Tracked Objects
          Mylenium Most Valuable Participant

          I think you have a misunderstanding here. The 3D Tracker creates a virtual camera that matches the one used to record the video, it doesn't track or reconstruct geometry. Any placement of 3D points is to that purpose only and utterly arbitrary based on the footage criteria like discrete edges, contrast and so on, not geometry.



          • 2. Re: Multiple 3D Tracked Objects
            Lone Lobo Level 1

            I understand the theory...at a kindergarten level. I just need to know how to handle multiple objects that I want to use with the same virtual camera. IE. What I want to do is to track multiple "Text" objects to different points on the same clip.  The "text" labels need to appear and disappear as the scene progresses.

            I can't seem to find any reference to adding more objects after going thru the process of analyzing the scene/selecting the plane and points/and then right clicking to add text/object/null.  I need to add more text/object/null's  and just don't know the mechanics of doing this AND attaching said objects to a different set of virtual reference points. 


            And yes, my ignorance is showing.  Just need some education or pointers to where to get educated.  My current resources are Adobe and Lynda.com  Both are not teaching me what I want to learn.

            • 3. Re: Multiple 3D Tracked Objects
              Lone Lobo Level 1

              While I'm at it, I'm having problems just formatting the text that I have created with 3d tracking.  Would it be easier for me to create the text in another program and link it to a null object?  Where are all the shadow and outline options I am used to in Premiere? 

              • 4. Re: Multiple 3D Tracked Objects
                Mylenium Most Valuable Participant

                Once you have the solved camera, there is no special requirement to use the 3D tracker points at all. It's a genuine 3D scene and any 3D layer, no matter whether it's text, a solid, footage or a 3D scene with Element 3D/ Cineware or a 3D-ish particle effect like Particular wil lrespect that camera. You merely need to enable the 3D layer switches where necessary. And "shadow and outline options" don't exist in AE. You have to use effectsand layer styles, but the latter actualyl break 3D rendering, so you may need to pre-compose or import your styled graphics as footgae from anotehr program. In any case, this has nothing to do with the tracker or any of that, your thinking is simply too locked into your Premiere mindset. You need to losen up and adapt. Most of that is basic stuff and can easily be learned by watching a handful tutorials, even some mediocre ones on YouTube...



                • 5. Re: Multiple 3D Tracked Objects
                  Lone Lobo Level 1

                  In the event anyone else is having the same problem I will state my findings.  In order to track more than one object to the same set of points, simply CTRL-D after selecting the text/object/null layer to duplicate your text/object/null layer after it has been created in 3D tracker. Then you can change the text or manipulate the object in the sepearate layer.  The object in the first layer remains unchanged and the additional layers are simply offset from the original text/object/null after you move them into place.


                  This is great if all of the objects in your scene absoutely maintain their relationship to each other as all layers are tracking the same points in your virtual camera layer (usually labelled 3D Tracker). 


                  Now I need to know how to track those different layers to different sets of points in the virtual camera layer.  IE. I want to attach 2 sponsor's names to 2 different race cars as they whiz past the camera.  They both can't track the same point as the race cars are moving independently within the shot and their spacial relationship to each other changes frame by frame.


                  Any help is appreciated and any successful procedure will be documented and reported back to this discussion.



                  • 6. Re: Multiple 3D Tracked Objects
                    Rick Gerard Adobe Community Professional & MVP

                    You are still not understanding how the 3D tracker works. It does not track objects in the scene and solve for their positions. In fact, if you have a big truck driving through your scene you need to exclude the truck from the 3D track.


                    The 3D tracker tries to solve the camera focal length, position, angle, roll, pitch and yaw for the camera that took the footage. If it successfully does that then you can insert 3D objects into the scene and AE's camera will track those objects just as if they were actually in the scene.


                    If, for example, you wanted to track the movement of the truck through your scene then you need to use planar tracking. You use Mocha for that. Planar tracking can track the movement, perspective, scew, roll and scale of different planes moving through a scene. From your descriptions that is what you should be using. The 3D camera tracker is just the wrong tool.


                    If I have completely missed the point then please let us know. It would really help if you could put your video up on Youtube or Vimeo so we could better understand what you are trying to do.

                    • 7. Re: Multiple 3D Tracked Objects
                      Lone Lobo Level 1

                      Hey Guys,

                      I don't exactly know how to respond.  I have a pretty good idea of how 3d Tracker creates a virtual camera and tracks points within that virtual reality that are mathmatically calculated from points in the real video.  What I'm trying to find out is if you can attach multiple objects (whether they be text, objects, or null objects) on multiple layers  to different sets of virtual points in the same tracker layer.  IE. many object layers with only one tracker layer.


                      In other words, how do I create multiple tracking boxes like I do with planar tracking?  Right now I just can't find the correct procedure for creating multiple "targets,ie bullseyes" in 3D tracker like I can do with Planar tracking boxes.


                      Also, just as an aside, why does the number of layers and objects offered to be created by right clicking the bullseye change dependent on how many points I select to define the plane I want to track to? 


                      Thanks for your patience as we walk thru this minefield of technical semantics.

                      • 8. Re: Multiple 3D Tracked Objects
                        Rick Gerard Adobe Community Professional & MVP

                        Take a quick look at this short example of attaching text to a wall and then addaching a solid to act as a track matte for the text as the camer moves around a corner.



                        Sorry about the lack of audio. I did this several months ago while waiting for a meeting at Starbucks.

                        • 9. Re: Multiple 3D Tracked Objects
                          Lone Lobo Level 1

                          YES, my question is HOW DID YOU GET THE 2ND bullseye target to appear.  THAT's my missing link!

                          • 10. Re: Multiple 3D Tracked Objects
                            Rick Gerard Adobe Community Professional & MVP

                            Make sure the 3D tracker is selected. The tracking points should show up. Just roll over or shift select tracking points. Then right click and insert whatever you want.