[Mike Clasby]

1)Here is a good place to start:

https://jjgifford.com/expressions/basics/index.html

2) And the Best One-Stop is Dan’s site:

https://www.motionscript.com/

The link, “Mastering Expressions” walks you through examples, he explains along the way.

See the bottom link, “Other Resources” for books and such.

3) And as always the AE Help Files:

https://livedocs.adobe.com/en_US/AfterEffects/8.0/help.html

Click on the “Expressions” link in the left column.

[Mike Clasby]

Corner Pin is a 2D plugin. Does the precomp need to be 3D?

I might not be getting the setup straight in my head, but how about 2D for everything?

Precomp the colored solid layer, then bring that comp in, one comp for all three colors, then apply corner Pin to that. Or you could even track the finger/thumb connections and tie the precomp to that with a corner pin track, no?

Here’s a tut for Perspective Corner Pin; it’s to change the writing on a sign but just use your thumbs as the corners ot the sign and pin the solid precomp to them:

Keep motion in perspective

https://studio.adobe.com/us/tips/tip.jsp?p=1&id=100241&xml=aft65cornerpin

[Mike Clasby]

Also… maybe this is a little easier, as you could slide the marker around as needed.

Marker Kills Expression
Set a marker with the asterisk key on the numeric pad.

n = 0;
if (marker.numKeys > 0){
n = marker.nearestKey(time).index;
if (marker.key(n).time > time){
n–;
}
}

if (n == 0){

//your expression here

}else{
value;
}

[Mike Clasby]

You could just Split the Camera layer and then deactivate the expression, or use one of the three solutions below; expression on/off at a given frame, with a checkbox, or at given keyframes.

And here’s a nifty Dan expression for starting and stopping an expression at a given frame:

startFrame = 145;
stopFrame = 241;

if (time >= framesToTime(startFrame) && time < framesToTime(stopFrame)){ wiggle (5,20) }else{ value } ----------------------------- Name: Dan Ebberts Date: Jun 13, 2006 at 9:39:46 am Subject: Re: animating expression on/off On way is to apply a checkbox control to your layer, keyframe the control on and off, and add an expression like this to your property: control = effect("Checkbox Control")("Checkbox") ; if (control == 1){ wiggle(5,50); // your expression goes here }else{ value; } Dan ----------------------------------------- Name: julian06 Date: Dec 15, 2006 at 10:17:53 pm Subject: Re: Start Expression after certain frame hi let's assume that keyframe 1 is at frame 60 and the second on is at frame 240. Now add this expression if (time >= key(1).time&& time<=key(2).time) { wiggle(1,50) } else{ value }

[Mike Clasby]

If there is no other layer below the video layer, apply the effects to an Adjustmment Layer (Layer>New>Adjustment layer), then trim the adjustment layer to the desired times with Alt [ and Alt ].

Alternatively you can Duplicate the layer(Ctrl D) then apply the effects to it and trim the effected layer accordingly. PS, turn off the dup’s sound.

Or split the layer (same as just above really) where you want to effect or not effect.

[Mike Clasby]

Your problem is you probably have the wrong kind of vertexes in the wrong place. Some are Smooth Points, have those little handles, and you need them for where the bulges on the Club come together; some are Corner Points, are for sharp cuts like V’s or the base of the club and have not handles.

You can change the type of vetice with the Convert Vertex Tool, looks like a little wedge or arrow head without a bottom.

Here is AE help for details:

https://livedocs.adobe.com/en_US/AfterEffects/8.0/help.html?content=WSFC7D7F78-4371-4917-A752-625CD403F666.html

Also, to get just one side, or only one of the Bezier handles to move, hold down “Ctrl” (giving you that Convert Vertex Tool) then grab the end of the Bezier Handle with that and you can adjust the one handle without affecting the other, to get those big club bulges to fit right.

With the right kind of point, Smooth or Corner in the right place you can get a tight fit on a shape with a minimum number of vertices with the Pen Tool… but it can be a pain, until you use it enough to be your friend.

Alternatively, if you can find a Club with Alpha all around it, use Layer>AutoTrace to create your mask, set Tolernance and Threshold to 1 or the lowest setting availble to get it as tight as possible.

[Mike Clasby]

Here is a Dan expression that is probably what you want. First keyframe the layer for the initial resize like from say 50% to 100%, then add a Marker at that 100% keyframe by hitting the asterisk key on the numeric pad (*). Then put the expression on Scale. The marker will trigger a little bump:

n = 0;
if (marker.numKeys > 0){
n = marker.nearestKey(time).index;
if (marker.key(n).time > time){
n–;
}
}

if (n == 0){
value;
}else{
maxDev = 10; // max deviation in pixels
spd = 40; //speed of oscillation
decay = 10.0; //how fast it slows down

t = time – marker.key(n).time ;
x = scale[0] + maxDev*Math.sin(spd*t)/Math.exp(decay*t);
y = x;

[x,y]

}

No marker, not bump, so asterisk away. Change the maxDev, spd, and decay to taste. The decay a 10 makes the bump quick, not much oscillation, a smaller number makes it oscillate longer.

If you want a little squish and squash action on the bump, instead of a uniform x and y bump as above, change lines 17 and 18 to this:

x = scale[0] + maxDev*Math.sin(spd*t)/Math.exp(decay*t);
y = scale[0]*scale[1]/x;

[Mike Clasby]

Look in you Temporary Internet Folder (PC) or the equivalent in Mac-land. Look right after you’ve viewed the tut, or as soon as it’s fully loaded. Copy there then paste to another folder to save.

Most are FLV’s or Mov’s.

[Mike Clasby]

Options:

1) If you hold down Alt (Option)you can reposition the track point but keep the same Attach Point, that should do what you want, methinks. Here’s that tut from Adobe:

Tracking obscured objects in video

https://studio.adobe.com/us/tips/tip.jsp?p=1&id=399&xml=aft6tracking

2) Or apply tacking data to a Null, then apply a new track to another Null (Null 2), then parent Null 2 to Null 1… linking them up, like Andrew does here:

https://library.creativecow.net/articles/kramer_andrew/Set_Extensions.php

[Mike Clasby]

Try this on Scale of the Speaker layer:

Audio = thisComp.layer(“Audio Amplitude”).effect(“Both Channels”)(“Slider”);
minAudio = 0;
maxAudio = 25;
minScale= 85;
maxScale = 100;
s = linear(Audio,minAudio,maxAudio,minScale,maxScale);
[s,s]

Set maxAudio to whatever the highest reading is on Both Channels of the Audio Amplitude layer. Twirl down the Slider to see the graph. The scale of the speaker will fluctuate with the audio from a scale of 85% to a scale of 100%, change the 85 and 100 as needed.

Is dat close?

I dunno if I’m looking in the right spot, the speakers on the Robot, but some of them scale in only one dimension, so try this for the last line to get x only scaling, like on the robot’s knees:

[s,minScale]