• Adobe After Effects Expressions

  cameras and nulls.

  Posted by Benito Sanz on August 7, 2005 at 5:59 pm

  hi all!

  i am a bit confused regarding cameras parented to null objects. i get the idea of using a null to control the camera, but what confuses me is that i’ve seen in some 3d tutorials here in the cow that both position in the camera and null are animated. my question is what parameter do you normaly use in the null object and what parameters in the camera when doing animations.

  thanks a lot.

  Benito Sanz replied 20 years, 11 months ago 3 Members · 10 Replies
• 10 Replies

• 

  Steve Roberts

  August 7, 2005 at 6:09 pm

  If I have a camera that orbits an object, I’ll probably parent the camera to the null and rotate the null’s Y-rotation parameter. Then, if I need the camera to look around a bit as it orbits the object, I’ll tweak the camera’s rotation paramters. I suppose it’s “rotate the null for the gross rotation, rotate the camera for the fine rotation”.

  That’s one way to do it …
  Steve
• 

  Rich Rubasch

  August 8, 2005 at 1:20 am

  Another way is to lock the Camera’s Point of view to the null, then wherever the null goes, the camera “looks”. then you can animate the camera by raising and lowering it and it will either be looking down at the null’s position or up at it.

  Rich Rubasch
  Tilt Media
• 

  Benito Sanz

  August 8, 2005 at 9:38 am

  thanks for your replies, how do you lock the point of interest to the null.

  thanks.
• 

  Steve Roberts

  August 8, 2005 at 10:53 am

  With expressions:

  1. Make the camera’s Point of Interest (POI) and the null’s position properties visible in the timeline
  2. alt-click on the POI’s stopwatch
  3. drag the POI’s pickwhip to the null’s position property (the word “position”)
  4. click anywhere else in the timeline to “seal” it and create the expression.

  Give it a go …
  Steve
• 

  Benito Sanz

  August 8, 2005 at 12:24 pm

  thank you very much steve for your help.
• 

  Steve Roberts

  August 8, 2005 at 2:10 pm

  Hope it works for you. 🙂

  Steve
• 

  Benito Sanz

  August 8, 2005 at 4:29 pm

  hi steve, why sometimes when i use a null to control the camera goes to a diferente position, like this sample in the link, why is so far from my layer.

  thanks.

  [URL=https://img36.imagevenue.com/img.php?loc=loc261&image=d32_muestra.jpg][IMG]https://img36.imagevenue.com/loc261/th_d32_muestra.jpg[/IMG][/URL]
• 

  Benito Sanz

  August 8, 2005 at 4:30 pm

  sorry for the link

  https://img36.imagevenue.com/img.php?loc=loc261&image=d32_muestra.jpg
• 

  Steve Roberts

  August 8, 2005 at 4:51 pm

  If the null is behaving strangely, you might
  a) have the parenting backwards: The camera layer should, under the “parent” coloumn, display the null layer.
  b) have the expression backwards. The expression should be in the camera layer in the timeline.

  Does that help?
  Steve
• 

  Benito Sanz

  August 8, 2005 at 5:10 pm

  sorry steve this is the link image.

  https://img2.imageweb.info/viewimage.php?file=/img2/oFd21000.jpg

Reply to this Discussion! Login or Sign Up