twinkling star effect

That definitely works! There's no one *right way* to do things and whatever works for you and saves you time doing it -- go for it!

Here's an idea to try. Add a Basic Title and select the text and replace it with spaces (I don't recommend ever entirely deleting text.) Add the Star 2 Effect to the Basic Title! Set up the animations with Amount, Frequency and Rate of Change. Every time you need a piece, blade off 2-3 frames of the title - you can use the onscreen control to position the star where you need it. You can make a "random variation" by picking a different Offset Animation. No keyframing. And you don't have to render a separate clip.

Any time you need more, you can just stretch out one of the titles and cut off the frames you need.

HTH

This effect is a single star, but you can add as many as you want to any clip (except transitions).

I've set it up to be free for 2 days:

https://fcpxtemplates.com/product/twinkle-star/

It features:

An OnScreen Control for positioning. The Color parameter controls the glow tint. The Spike Angle rotates the star; Spike Opacity, Spike Width and Epsilon you'll have to tinker with to get a feel for.

Scale is the best way to resize this effect. You can get away with up to about 150 or so percent and still have a clear star, or you can push the scale for very brief periods of time.

Opacity -- use it to time its appearance in the effect.

Blend Mode allows you to mix the star in the media (you also get a Color Mask and Shape Masks if needed).

Slant lets you off-angle the spikes (it's a nice touch).

Amount is the Amount of "twinkle" in size. Frequency is how often size changes (it's random so it's not just back and forth). Rate of Change is how much change is introduced to the Amount governed by the Frequency.

Start Anim % and End Anim % allows you to set the time within a clip at which the animated portion is displayed. Depending on how long the clip is will determine how long a "percent" is. The easiest thing to do is position the playhead and move the Start Anim % slider until you just see movement. Same with the End Anim % and where you want the animation to stop.

The Offset Animation control is interesting. It's like a mini - playhead that you can use to create a "different start" of the animation OR you can keyframe it to accelerate any animate. It will even animate if you set the start anim % to 100% or the end anim % to 0 (in other words, you turn off the twinkle effect but still have Amount, Frequency and Rate of Change for animation.

So there's a lot of things you can do to create the effect you want, but you have to do it for each star you add. (Tip: set up one, then Copy the clip, then Paste Effects [option-command-V] as many times as you need for the number of stars you want to use, then make adjustments to parameters to make them different from each other. You can also use Paste Attributes [command-shift-V] and select the Star 2 effect from the list if you have other effects you don't want to duplicate.)

HTH

Installation instructions are here: https://fcpxtemplates.com/installing-plugins-for-fcpx.

It's fairly general purpose and there aren't any instructions for use — it's just like any other basic object. Most of the parameters can be keyframed (except blend mode).

One way to go would be to keyframe the Opacity parameter, but I'm going to skip that because you have a shape to follow and it sweeps over the stars, so here is a tutorial for how to do that (with one star — you'll have to repeat the process for the second start as well since they are both individual Effects.)

https://youtu.be/C2niy_drKXY

There are ways of setting up any number of stars and creating a shape mask that will do them all at once... but that will require more tools (that almost nobody but myself has, and ASC rules forbid me from "advertising" them).

Okay - I read the comment.

Keyframing is the same for all parameters. If you need to have the star turn on and off, then you keyframe the Opacity parameter (from 0 to 100% and back). To keyframe movement, you have an OnScreen Control for position, so all you have to do is set the playhead where you want the star to start moving then set a keyframe. Move the playhead any amount of frames and then use the onscreen control to position where you want the star to be at that time. Final Cut will automatically set a new keyframe for the object at that position. When you move the playhead between those two points in time, you will see the object animate between the two keyframed positions.

Another example will be setting the Start Anim % to 100% (effectively turning off any animation) and if you have Amount, Frequency and Rate of Change set to greater than 0, you can keyframe the Offset Animation to create the animation at faster or slower speeds — but you can also keyframe a particular size at one keyframe and exactly the size you want at the end of the keyframed animation.

You can continue to manipulate keyframes in time to create more varied animations as well and you can keyframe *every* frame (but I don't recommend it!)

Once you add a keyframe and move the playhead off of it, a small arrow (rather subdued gray) will appear showing the direction of the next keyframe in time. Clicking on it will set the playhead back on that next keyframe. If more than one keyframe exists, the arrows will continue to show until you reach the last one in the direction you're going. In this way, it's easy to maneuver in time if you need to make corrections.

There is also a feature in Final Cut that let's you "edit" keyframes called the Video Animation Editor. You get to it by selecting a clip and typing Control-V. It pops up a list of Effects and there is a downward pointing "arrow" (of sorts - looks more like a flat 'v') that you can use to open a menu of all the keyframable parameters in each effect. You can click and drag on the diamond shapes to new timing positions. Some keyframes allow for "smoothing" in which case there will be another small icon all the way at the right side of the editor that you can open and set the transition from one keyframe to another with Easing (In/Out/Both) or as Linear.

You can Clear all keyframes on a parameter by selecting the downward pointing arrow to the right of the keyframe (area) and selecting Reset Parameter.

The best way to learn this stuff is to get in and try out a few different parameters (you can always reset to default easily) and just get a feel for it. It's easy. It's quick to learn. About the only stumbling block is when you get into situations where you need to Add "Stop" keyframes. Let's say you want to move an object to a point on the screen and stop for a period of time, then continue on to another location afterwards. You would set a keyframe at the Start position, then move the playhead, and move the object (setting an automatic keyframe). You would need to move the playhead to the end of the "paused" movement and manually set another keyframe on the parameter in the inspector (a "stop" keyframe), then you can continue creating new movement keyframes by simply moving the playhead and moving the object to the new position. If you don't apply a stop keyframe, then FCPX moves the object continually... see what I'm getting at?

Keyframes are essentially the same no matter what parameter they are applied to... Some parameter types cannot be keyframed (menus, for example), but every parameter that can be keyframed will show a white diamond outline with a period in the center when you mouse over the line the parameter is on in the inspector. A Set keyframe is (I see) Yellow (some have described it as an orange color.)

Manually clicking on whatever keyframe symbol shows (unset, set and "active" [which appears green when the mouse is over a set keyframe]) will toggle it either on or off.

HTH

If you look at the tutorial video again, I have the video set up for B&W. A Circle passes over the video that's in Full Color much like your circle displaying the truss in the scene.

Star 2 is an Effect. Only Effects have access to "Effects Masks" (the Color Mask and Shape Mask options). When you add a shape mask to the Star effect, by default, only what's inside the Mask region is visible (partially visible inside the "Feather" ring). These "onscreen controls" for the shape mask are very much like several onscreen controls available with Filters in Motion.

The actual Shape controls for a mask have 4 green dots around the circumference. There's an extra control at the top edge that if you drag it out, the shape turns into a square. Although there is a center point (very small) onscreen control for the shape mask, you can actually click anywhere inside the mask region to move it in the viewer.

By animating (keyframing) the position of the shape mask, you can show and/or obscure the Star (anything in any effect that has Effects Masks).

In my tutorial video, I use the Full Color circle as the same thing as your reveal circle. I match the outer edge of a Shape mask to the Edge of the "reveal circle". I demonstrate how to keyframe the Shape mask to pass over the Star to reveal it while the full color (reveal) circle is passing over the star. As it leaves the star, I follow the shape mask on the other edge.

The Amount, Frequency, and Rate of Change are just parameters used to animate the size of the star and have nothing to do with it turning on and off.

If you're not using the Shape Mask, you turn the Star on and off with the Opacity parameter -- 0 for off, 100% for full on. In general, turning it on and off would be setting the opacity to 0, move the playhead one from forward and set the opacity to 100%; move the playhead again to the frame just before you want to turn it off, set a keyframe manually on that frame, then move the playhead one frame forward and change the opacity to 0 again. However, since you have a circle reveal that moves, if you turn on and off the opacity, it will not look quite the same because you have to change its state inside the circle reveal instead of letting them "pass" into and out of the reveal as if they are "always" on in the "other world".

Try not to overthink this — it's a lot like learning to install a template — once you do it, it's "not a thing" anymore.

By the way, Amount, Frequency and Rate of Change **all** have to have non-zero values in order for any of them to work. By default, the only one of the three that has a default starting value is Rate of Change. Start by cranking the Frequency up to 100 then start adding Amount. You can type the / key to make the clip you have added Star to play from the beginning and repeat when it gets to the end, so you can keep adjusting these parameters to get the look you want.

HTH