8 Replies Latest reply on Jun 9, 2014 2:26 PM by rhidianp

    Tracking solid color

    rhidianp

      How do you track a random area on a solid color? For example, I want to import a photograph of the sun and layer it on top of the video. I want it to track an area on the blue sky. I tried motion track in AE and mocha. The tracking doesn't stay still.

        • 1. Re: Tracking solid color
          Rick Gerard Adobe Community Professional & MVP

          I"m very confused. Do you want to insert a photograph of the sun in a video shot with a moving camera??? If so then there needs to be something in the video that you can track. Then you apply the tracking info to the 'sun'. Another option would be to use Camera Tracking to analyze the camera movement then find a target as far away from the camera as possible and add a null and a camera. Make your sun a 3D layer (it may disappear) then hold down the shift key and make the null the parent of the sun. The sun will snap into position. Now just drag it into the spot in the sky where you want the sun to be.

           

          Another option is to stabilize the shot so that it is not moving, then add in your sun, then re-introduce the motion to the shot. Here's a quick tutorial that shows how to do this. The target would be the sun layer. You would not set up a track matte, but you would just find something in the movie that you could track to stabilize the movie so that it does not move. If there is a lot of camera motion then you would need to use two points. Then you would add your sun and follow the steps to add movement back to the movie and apply the inverse of the motion to the sun.

           

           

          If none of these techniques work for you please give us a better description of what you are trying to do.

          • 2. Re: Tracking solid color
            rhidianp Level 1

            I think you understood what I am trying to do. I have a clip that tilts down a little, so when I add the sun, it moves with the clip. I just want the sun to be anchored in one position without any movement. Could you please explain that first step a little more. Thank you.

            • 3. Re: Tracking solid color
              Rick Gerard Adobe Community Professional & MVP

              Find a point on the shot that you can apply the After Effects tracker to. I tracked the girls face in the video. Then select Stabilize. The horizon should now stay in one place. Add your sun and move it into position the same way that I moved the target over the girl. Skip the parts where I create a track matte and a pre-comp. Add a null. Reveal the position property of the null and attach it to the anchor point of the tracked footage using an expression. Simply drag the pickwhip to the Anchor point as I did in the movie. In the tutorial your sun would be the pre-comp. Then simply parent both layers to the null. That will remove the stabilization from the shot you stabilized and add the motion to the sun layer.

              • 4. Re: Tracking solid color
                rhidianp Level 1

                The tracking was still very shaky after I selected stabilize. I'm trying to manually stack all the keyframes on top of each other now.

                • 5. Re: Tracking solid color
                  Rick Gerard Adobe Community Professional & MVP

                  Shaky stabilization is most often caused by trying to analyze too small an area. The other problem may be that you are using highly compressed footage with a lot of compression and motion artifacts. Another problem may be that you are simply picking something without enough detail in the shot. The short tutorial that I posted shows me expanding the tracking area, the inner box, to include almost all of the girl's face. That is what it took to get a good result.

                   

                  If you could post a screenshot of your scene I will suggest some tracking points.

                  • 6. Re: Tracking solid color
                    rhidianp Level 1

                    I tracked a nearby hanging leaf beautifully. I'm just having problems applying that tracking information to my null object. How do I transfer the tracking information from the leaf to the blue sky area, the area where I want to put my sun pre-comp?

                     

                    I'm also getting this message when I click "Apply": After Effect error: internal verification failure,sorry! {can't evaluate expr on a parentless stream!.}

                     

                    The clip is not compressed.

                     

                    Thanks.

                    • 7. Re: Tracking solid color
                      Rick Gerard Adobe Community Professional & MVP

                      If you are stabilizing the footage then removing the stabilization as I did in the short tutorial you do not apply tracking info to anything, you add a null then use an expression to tie the null position to the anchor point of the tracked footage then you make the null the parent of the sun and the tracked footage. This removes the stabilization from the footage and adds the movement to the sun layer.

                       

                      Take a very careful look at the tutorial that I posted. This is a very simple procedure.

                      • 8. Re: Tracking solid color
                        rhidianp Level 1

                        I got it to work. I performed the same process. The only thing I could think of is when I was pick whipping the null position to the anchor point, the whole clip was highlighted, not just the anchor point.

                         

                        Thanks.