Camera position moves when 2 keyframes are set at the same position?

Camera position moves when 2 keyframes are set at the same position?

by Scott Green

on Aug 24, 2009 at 11:08:38 am

I'm finding using cameras a bit frustrating lately, especially when working in 3D space in After Effects.

Here is what I'm struggling with, hopefully you can help me understand what's happening.

I set a keyframe for the anchor point and position at the start of the camera movement and then use the camera move tools (using the C button) to get to the position where I want the camera movement to stop on a subject that I have placed (with no movement applied at all) in 3D space.

Everything is fine at this point but I want the camera to hold it's position for a few seconds and then move to another position, so I copy the last keyframe and paste them where I want the start of the next movement to take place and then after that I carry on to the next movement.

But sometimes, in between the keyframes that I've copied and pasted (with exactly the same coordinates) the camera moves position (often when I have eased the keyframes).

Why is this happening and how can I stop it?

And how can I ease the camera movement in and out without the cameras position changing when I don't want it to?

Hope you can help, thanks.

http://www.splurj.com

Re: Camera position moves when 2 keyframes are set at the same position?

by Todd Kopriva

on Aug 24, 2009 at 2:50:40 pm

from "Controlling change with interpolation":

"In some cases, the Auto Bezier spatial interpolation for Position keyframes can cause undesired back-and-forth (boomerang) motion between two keyframes with equal values. In such a case, you can change the earlier keyframe to use Hold interpolation or change both keyframes to use Linear interpolation."

(The same page also points to some videos by Aharon Rabinowitz back here on the COW that demonstrate and explain the issue.)

If a page of After Effects Help answers your question, please consider rating it. If you have a tip, technique, or link to share---or if there is something that you'd like to see added or improved---please leave a comment.
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Todd Kopriva, Adobe Systems Incorporated
putting the 'T' back in 'RTFM' : After Effects Help on the Web
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Re: Camera position moves when 2 keyframes are set at the same position?

by Chris Buttacoli

on Aug 24, 2009 at 3:43:07 pm

One way to work is to only use linear key frames until your camera movement is the way you want it, and when your done, easy-ease all the keyframes.

Re: Camera position moves when 2 keyframes are set at the same position?

by Scott Green

on Aug 24, 2009 at 4:17:45 pm

The tutorials that were posted were really helpful and I knew it must have been something to do with the bezier curves but I had no idea about the interpolation settings of even what they were so thanks for clearing this up, problem solved! ;)

Thanks

http://www.splurj.com

Re: Camera position moves when 2 keyframes are set at the same position?

by Karim Daire

on Aug 24, 2009 at 8:21:16 pm

I had the same problems with a 3D project just this week and wanted to throw my laptop out of the window at times until I realized that AE tends to mess up interpolation when you work with eased keyframes. If you set keyframes and ease them... everything is fine. If you change eased keyframes or copy them (like I guess you did with the same position twice) you get strange results. It took me a while to realize that you have to set back all messed up keyframes to linear interpolation for time AND position (Right klick+Keyframe interpolation). I knew the problem soon but It took a while to see I had to change both, now it works fine and i finished the project without any harm to my hardware! ;)

Hope this helps!

Karim

-Karim-