• Adobe After Effects

  Problems with tracking background with mocha & 3D camera tracker

  Posted by Kasper Nørgaard on March 19, 2013 at 12:19 pm

  I am working on a movie and i am running into some problems. I hope someone can help me. I have worked on a small clip in about 30 hours now and nothing seams to work.

  I have a clip with a “handheld” camera (shoulder rig), and i need to track a wall where blood from a head shot is splashed.

  I have tried to use Mocha through After Effects CS6, tracked the background and sometimes i can see that it doesn’t follow that good and changes the shape and position a little bit.
  When i copy to clipboard and paste it into a null object in AE it is even worse and sometimes it doesn’t follow the background at all.

  I have also tried to use the Tracking i AE, but that’s not good enough.
  Then i found 3D camera tracker in AE, which i tried to use, but that is even more confusing. When i track the clip and right click on the position i want to follow from the tracking points and create a Null object and a 3D camera or create a Solid and a 3D camera, it seams to follow the background i have been tracking. But when i parrent my blood layer to the new Null object, it seams to have a different tracking pattern. The null object still follows the background, but the blood layer which i have parrent to the null, does not follow the null.

  Any one who can help me, because i am out of ideas.

  Best regards
  Kasper

  Kasper Nørgaard replied 13 years, 5 months ago 2 Members · 2 Replies
• 2 Replies

• 

  Vishesh Arora

  March 20, 2013 at 12:01 pm

  hello Kasper

  After pasting the Tracking data to a Null Object in Ae from Mocha, Delete the Anchor Point Keyframes. It should work 🙂

  Vishesh Arora
  3D and Motion Graphics Artist
  Films Rajendra

  Blog:
  https://digieffects.wordpress.com

  2011 3D Demo Reel:
  https://www.youtube.com/watch?v=lHPgIJU_BR8
• 

  Kasper Nørgaard

  March 20, 2013 at 3:01 pm

  Hi i already did that.
  I made a new tracking in mocha yesterday, where i tracked the background and made two track layers on the two persons and placed those layers over the BG layer, so they don’t disturb the BG tracking layer. I unchecked the gear icon the two person layers, so there will be no tracking data for these, but only the background. Perspective in the motion settings is also checked.

  Afterwords I checked in Mocha, that the BG Tracking shape followed the BG in the clip and it did. But when i copied to clipboard (achtor point, position, scale, rotation) and paste to Null object. Delete the achtor point from that Null and parrent a blood layer to the Null.

  But the blood layer seams to scale a bit wrong and the blood layer also rotates a little a certain place in the clip. (a little, but still too much rotation)

  I don’t understand what the problem is, because the tracker seams to follow in mocha

  

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