• Adobe After Effects

  Expression ?

  Posted by Dan on December 22, 2005 at 4:06 pm

  I’m trying to change/ad control to an expressioin. The expression came from a turtorial in which the camera rotates (in 3D space) and zooms in and out.

  [Math.sin(time)*1007,120,Math.cos(time)*1007]

  I wondering if there is a way to ad some control to how fast the camera rotates and how fast it zooms. The expression came from this turtorial:
  https://forums.creativecow.net/cgi-bin/page_wrapper.cgi?forumid=2&page=https://www.creativecow.net/articles/al_khatib_talid/volume_meter/index.html

  I’m fairly new to working with expressions and am trying to understand how to control them more.
  Thanks.

  Mike Clasby replied 20 years, 4 months ago 2 Members · 1 Reply
• 1 Reply

• 

  Mike Clasby

  December 22, 2005 at 8:18 pm

  That’s a clever little expression. I don’t really know how to write expressions, but through trial and error you can change expressions, by multiplying or dividing (or adding to and subtracting from) parts of the expression.

  To open the expression, select the layer (camera), and type “ee” quickly. You’ll see the expression appear. Double click it to open it for editing. Now with the cursor you can change things.

  [Math.sin(time)*507,120,Math.cos(time)*507]

  make the 507’s smaller, and the camera moves closer, larger and its farther away.

  Changing the 120,changes the angle the camera sees the audio cube from.

  By multiplying (*5) or dividing the time (/5), changes the speed the camera rotates around.

  [Math.sin(time*5)*507,120,Math.cos(time*5)*507] speeds it up 5 times.

  [Math.sin(time/5)*507,120,Math.cos(time/5)*507] slows it down by a factor of 5.

  Change things and see what happens on the screen. “Ctrl Z” to undo any unwanted changes and get back to the original. If you make the expression unusable AE will tell you.

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