How to use AE to quickly create a lively little dot

When we use AE to do demo animation, to show that the trajectory of our fingers often introduce a small dot.

The drawing of small dots is often the last step of our demo animation,

Then the problem comes: in the face of the various animated layers already done, various displacements, various motion curves.

How do you draw a small dot with a "hand"?

First you have to draw a circle first, according to the finger position you want to simulate the key frame animation, so far everything is very smooth, but the biggest headache is that you have to make "with hand" dot, before the "proud" of the various coquettish movement curve now become a variety of "pits." Well, bite the bullet and take some time ....

Hard to finally put the small dot right, the output ... At this point you have to pray not to rework, or you can only toss it.

A bit of AE based students may feel that the above method is too simple and rough, direct to small dots and target layer to do child parent link is not all right?

This approach allows two layers to be completely "synchronized", but the problem comes again? The hand is with the hand, but this kind of animation gives a very stiff, mechanical feeling.

Obviously the full synchronization of the animation is not what we want, if we can add a little bit of lag, delay, as we do in real life mobile phone, there is no?

How to draw a "hand" and "vivid" dot?

The first step is to use the dot as a child of the target layer, and then I'm going to introduce a magical guy "time Warp" (Effect > Time > Time Warp)

Tip: The time warp effect can only be used for shape layers, the bitmap layer does not seem to work?

After you add a time warp effect to a small dot layer, the other parameters in the panel can be kept by default, focusing on the speed parameter.

We set the "speed" parameter to 100, where we can see the effect of a small dot and a target layer in full sync.

The following figure we set the "speed" parameter to be: 98, 100, 103

We can conclude that when the time warp "velocity" is <100, the movement time of the small dot will lag backwards, and when the speed is >100, the movement time of the small dot will push forward.

So I usually set the speed to >100 (101 or 102) to simulate the subtle lag of the finger-operated screen.

It is not easy to complete our expected "with hands" and "vivid."

and the benefits of achieving this approach are:

1. Small dot position I can change at any time;

2. Small dot delay speed I can change at any time;

3. There is no need to consider the small dot animation path and animation curve, the target layer how to move small dots on how to move.

When the speed is set to 101, you can simulate the effect of a lifelike finger-operated screen.

But the problem is, when I link the layer directly with the child, the small dot's position attribute is linked at the same time, scaling, rotation and other attributes are also linked, as shown in the following figure. (transparency is not linked)

To solve this "limit" we can also play this way:

We can add a "null object" layer to serve as a "bridge" for small dots and target layers.

Create a new empty object and select it, click "P" to bring up the position attribute, and then hold ALT + the left mouse button (the following figure pen) key Click the position of the key frame weights icon, the following figure:

The position attribute will pop up a line of expression menu, also have a parent link icon, at this time we click on the Position property expression of the parent icon to drag to the target Layer position properties, release the mouse, Shintou layer position attribute and Target layer position attribute link on. Then we move the DOT layer parent to the empty object layer, so we break through the "complete" link with the layer parent to the layer, as shown in the following figure. (Here I do not directly with the location of small dots to link the target layer, you can try why I do not do this directly)

With this in mind, we don't have to worry about scaling the target layer, the rotation properties will have an effect on the dots, I can make more changes, and the following figure adds a rotating keyframe animation to the target layer: