Tweaking keyframe velocity VERY smooth

[Aharon Rabinowitz]

A few thoughts –

You should make them continuous (as you;ve done), but then (still in the velocity dialog) set the influence to have 33.33% going in and out. This is the same thing as if you grabbed hold of the curve handles and pulled them out further from the keyframe – thereby stretching out the curve, and smoothing the velocity more around the keyframe so that going in and out, it is one continuous move. This will, however, effect the curve further out on both sides to compensate for the changes.

For example: you have to go from point A to B to C. If the whole thing takes 10 seconds, and you tell it to slow down going into and coming out of point B (by controling the velocity curve), then closer to A and C, it will have to move faster to make up for the time it lost going through B. 10 Seconds is 10 seconds, so if it gets more time at B, then A and C have to go faster.

If there are only 2 keyframes, consider making them Linear (spatial, not temporal).

Another posibility is that there is a bad curve in the motion path.

Bezier Keyframes often get wierdness that comes from AE trying to create a logical curve from the position data – unfortunately it’s not often what you want. You may not see the dots on the curve going off if it is only 1 frame of badness.

Try to grab hold of the keyframe’s curve handle and set it right. Or, if this is an option, and won’t kill the motion, make the keyframe spatially linear.

—————————————-
Aharon Rabinowitz
aharon(AT)yahoo(DOT)com
http://www.allbetsareoff.com
—————————————-
Creative Cow Master Series DVD
particleIllusion Fusion Volume 1
available @ http://www.pIllusionFusion.com

[David Modijefsky]

Thanx again Aharon. ‘Good’ to hear to hear AE sometimes messes up curves. I was doubting myself. I’m not at the machine right now but I’ll try 33,33%. I did try 50% and 0% which sounded logic to me. For my understanding what’s the magic about 33,33%?

[Aharon Rabinowitz]

It’s not a question of magic. And there’s no right amount of influence – it’s only whatever makes your curve work. I suggested 33.33, because if you check the velocity of an easy ease or ease in/out keyframe, you’ll see they use that amount. I discovered that a while back, and I find 33.33 is a good number to start with becasue it takes a little but leaves enough for the rest of the curve to run fairly smoothly.

I should mention that if you don;t have a lot of time between 2 keyframes, in many cases, depending on the distance between the keyframes in space, no amount of smoothing can help – you can’t have 12 camera motions over 1000 units aprt in 3 seconds, and expect to get smooth motion. Even if the curve itself looks smooth, it’s still a lot of motion in very little time.

In other words, all of this may be moot – you may need to space out your keyframes a little.

Oh, and i forgot, Make sure that all of your keyframes line up – camera, and aim (Point of Interest), and if you have nulls controlling it, those too. And make sure that if you are playing with the velocity of one, the others might need to be tweeked as well, or you will have exagerated motion at one end of the camera with smooth at the other, which is a recipe for a bumpy ride.

—————————————-
Aharon Rabinowitz
aharon(AT)yahoo(DOT)com
http://www.allbetsareoff.com
—————————————-
Creative Cow Master Series DVD
particleIllusion Fusion Volume 1
available @ http://www.pIllusionFusion.com

[David Modijefsky]

Thanx Aharon. On a stretch of around 20 seconds I’ve only got only 5 kf’s for tilting up/down so that should be pretty modest. The other keyframes for zoom (camera itself) are only four. At the points involved the kf’s are aligned. I also zoomed in on the motionpath on the tilt-null but it’s very difficult to spot a glitch there since the path is straight vertical. Anyway, The motion is slightly smoother now and I hope I can get away with it.