[Jeffrey Lejune]

Oldie but a goodie.

I was having this problem. I needed to keep the sweep’s spline in subdivided intermediate points to keep it looking good. Xpresso wasn’t allowing the align to spline % to match with the end growth % is the viewport display.

I saw this post and I duplicated the spline and changed the duplicate’s intermediate points to uniform and the Xpresso for the align to spline % started to match the end growth % visually.

Thanks!

[Jeffrey Lejune]

Found the answer on how to bake properties of the morph camera here https://monoplex.tumblr.com/ look for his blog post about “Baking Camera Morph”

Right Click the “Morph Camera” (in the timeline – not the tag) and choose “Add Property Tracks” and add Focal Length and Focal Distance. In the bake function you need the parameter check box checked.

[Jeffrey Lejune]

This is kind of working for me. I’m morphing between two cameras but each camera has a different “focus distance” parameter. In the bake dialog box I have the parameter checkbox checked but the baked camera only has the “focus distance” of the second camera and no keyframes for that parameter. Can’t find anything in the help files for the bake objects function that explains what the parameter checkbox is suppose to do.

[Jeffrey Lejune]

Thanks for the expression script examples. I see your point how an if/then statement keeps it simple and to switch the command based on the condition.

I have experience writing AS3 OOP for web mograph with flash back in the day. Sometimes I feel like it’s hard for me to apply knowledge of simple programming over to AE expressions. Slight differences in syntax and the fact that I don’t know all what I can manipulate through code just yet. I’m slowly coming around though.

Your insights have helped!

[Jeffrey Lejune]

Ahh… I see your point and thanks for the further explanation. Based on that I shifted the layer left past time 0 and then began to see results when I changed T to a negative.

The only limit at this point i see is how far back in time (left) I shift the layer or the keyframes for Angle. For example the beginning of the layer (or just the key frames for Angle) is shifted to a time of -20. I don’t see a result when manipulating T lower than -20.

So now I’m curious about your last statement:

“The angle control could have a different expression that also creates values before time :-)”

I’m not sure how to formulate that expression but would interested to know how to get it to output all the way to -infinity time. Not for a particular reason at the moment but there could be a use somewhere down the road.

[Jeffrey Lejune]

After a 2nd look through your 2nd explanation I also now understand why T would never work as a negative value bc the Timeline would never be have a negative value…. You’re looking for what the angle would be at a certain time based on that loop. We can’t go back past time of 0…. right? You can go from 0 to 1, etc… as well as going from 2 to 1 to 0 to get the rotation to go the other way.

but time travel to before the timeline start’s (negative value of T) isn’t possible… Hah!

[Jeffrey Lejune]

I’m getting it. Writing out comments of my observations on different iterations of the effect on duplicate layers helps.

I’m enjoying experimenting with the Angle control keyframes (timing & easing) as well as the value graph easing for the slider t control effect.

Super helpful. Thanks for the lesson!

[Jeffrey Lejune]

This was helpful so I wanted to say thanks?

One question is why you you selected the values of 0 at 1s and 4 at 5s?

Does it have something to do with the fact that the original time of the rotation from the previous explanation was 1 sec based on 30 fps?

So you get 4 rotations btwn 1s and 5s because of the 1 sec key framed looped animation. When I changed the value at 5s to 2 I got 2 rotations.

Just trying to understand the math incase I wanted to stretch things out or compress them.

[Jeffrey Lejune]

Thanks for taking the time to address this Dan. I will give it a try and let you know.

[Jeffrey Lejune]

Hate to drag something up from the past but I ran into this issue tonight and found this post which describes my issue almost exactly. I spent hours setting up a rig that would be controlled by the expression controls in the main comp. I can see the items in the precomp move when I scrub the sliders but as soon as I key frame nothing happens. Wonder if you ever got down to the bottom of what was going wrong.

Thanks