• Adobe After Effects Expressions

  changing time elapsed based on camera angle

  Posted by N8wn8w on April 11, 2007 at 11:56 pm

  changing time elapsed based on camera angle – I am creating a kind of a fake 3d world .. and I have a comp with 4 frames that have different 3d views of an object .. I am moving a camera through space and based on the angle of the camera I want to use time elapse to jump to a specific frame to give the illusion its real 3d .. so I am trying to figure out how to write the script with expressions

  something like

  if(camera_angle >= 0 && camera_angle < 90){ mycomp.gotoandstop(1) }elseif(camera_angle >= 91 && camera_angle < 180){ mycomp.gotoandstop(2) }elseif(camera_angle >= 181 && camera_angle < 270){ mycomp.gotoandstop(3) }elseif(camera_angle >= 271 && camera_angle < 359){ mycomp.gotoandstop(4) }

  Dan Ebberts replied 19 years, 1 month ago 2 Members · 3 Replies
• 3 Replies

• 

  Dan Ebberts

  April 12, 2007 at 1:51 am

  Assuming that you are rotating the camera on its y axis, your time remapping expression will look something like this:

  camera_angle = thisComp.layer(“Camera 1”).transform.yRotation;
  (Math.floor(Math.abs(camera_angle%360 + 360)/90)%4)*thisComp.frameDuration

  If you have it set up so your camera is the child of a null positioned at the center of the scene and you are rotating the null on its y axis, the expression should look like this:

  camera_angle = thisComp.layer(“Null 1”).transform.yRotation;
  (Math.floor(Math.abs(camera_angle%360 + 360)/90)%4)*thisComp.frameDuration

  Dan
• 

  N8wn8w

  April 12, 2007 at 2:18 am

  hey Dan,

  thank you very much!

  .. this is extremely helpful … and gives me a better eye of how the syntax works
  can you point me to an online resource that has can help me out with the syntax (properties, methods, etc)

  Thanks
  n8w
• 

  Dan Ebberts

  April 12, 2007 at 3:09 am

  I don’t think there’s a better resource for the attributes and methods than the user guide/help. It’s not big on examples, but it’s got pretty much everything. Combine that with a good JavaScript reference and you should be good to go.

  Dan

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