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 Animating a "head-bob" on Oct 7, 2010 at 8:59:18 pm

I am creating a 3d scene in AE and am trying to have the camera "walking" through it, looking at a few various text objects along the way. I was wondering if there is a plug-in or any tutorials for creating the "walking" effect, kind of like what you see in FPS games ala Doom/Wolfenstein/COD4 when you are running or walking.

Thanks for any ideas!

Good Day
http://www.mattsepeta.com

 Re: Animating a "head-bob"on Oct 7, 2010 at 9:50:39 pm

so you just need the camera to bob up and down...

an expression like this for the camera's position would effect just the y-pos and allow for further keyframing for the position:

f = 1 // bob frequency in times per second
a = 20 // bob amount in pixels
y = Math.sin(time*Math.PI*f)*a;
value-[0,y,0]

just modify the values for frequency and amount

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW

 Re: Animating a "head-bob"on Oct 8, 2010 at 6:30:25 pm

Thank you, this is perfect! I added this to the camera layers position than have a null as the camera parent to do the actual moving around.

Thanks again!!

Good Day
http://www.mattsepeta.com

 Re: Animating a "head-bob"on Oct 8, 2010 at 6:54:39 pm

Sorry, one more quick question- How do I "hold" the expression? I am entirely new to using expressions. I tried putting a "toggle hold keyframe" at the point where I want the "bobbing" to pause for a bit, but it did nothing...

Good Day
http://www.mattsepeta.com

 Re: Animating a "head-bob"on Oct 9, 2010 at 5:09:20 pm

unfortunately that gets into a pretty tricky expression. i thought at first i could link the expression to the null's speed, the idea being that if the null's speed was zero, then it would stop bobbing, but the math is really not that simple...

what you could do is add a slider expression control to the null, then use the expression pickwhip to link the slider control value to the f variable in the expression. then you can keyframe that slider to match the timing of the position keyframes. a 0 value will stop the bobbing.

you might also inquire in the expressions forum to see if somebody who is better at expressions can create one that works with speed, or some other method to automatically stop and start the motion as the null moves.

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW