Here's how to combine various features in Alight Motion to make a simple shine or light sweep effect on a text layer. You can use the same technique for other kinds of layers too.
Here's what we'll be making:
Let's get started!
Step 1: Make a text layer
Use a color that's darker than whatever you will use for the shine (typically, the shine will be white, so use a color that's dark enough to see a white shine on it. Here, we've just gone with the default gray color).
Step 2: Add a box shape on top of the text layer
You'll want to adjust the shape so that it's tall and thin. Make it taller than the text, and about half as wide as you want the final shine to be (this box will be half of the shine).
Step 3: Add a gradient fill inside the box shape
With the box shape selected, tap Color & Fill
Then choose the gradient option:
The gradient is black and white by default, and you can leave it set that way. Drag the handles so the gradient runs perfectly horizontally, like this:
Step 4: Duplicate the Shine Layer
Tap the back button to return to the option menu (the first screen when you select the shine layer), and tap overflow menu (the three dots) at the top right of the screen:
Choose the Duplicate Element option.
Now you'll have two copies of the layer:
Step 5: Flip and position the copy
Select one of the shine layers. Then, in the same overflow menu (three dots menu) choose the Flip Horizontally option:
Position the copy to the right, to mirror the original:
Step 6: Group and rotate the shine layers
Select both gradient layers (to do this, make sure no layers are selected then Long-press one layer until a green box appear, then tap the other to add it to the selection):
Tap the icon to make a group of the two layers.
Then select the group, go to Move and Transform and use the rotate option to slightly tilt the group to one side:
Step 7: Animate the shine
Use keyframe animation to animate the position of the shine layer so that it starts on one side of the text and moves to the other side. If you've never used keyframe animation before, you can learn how in the Getting Started: Part Two tutorial on our YouTube channel.
Step 8: Mask the shine
For the next step, select and duplicate the text layer (see step 4 above for how to duplicate a layer).
Move the copy to the top of the timeline, by long-pressing the grip icon at the right end of the track and dragging upward:
Next, select the top text layer and the gradient (again, by long-pressing one, then tapping the other).
Finally, in the overflow menu, choose Create Masking Group.
Step 9: Change the blending mode
You'll notice that the shine effect still includes the dark black edges from the gradient.
To get rid of those edges, select the group and change the blending mode to Screen in the Blending & Opacity menu.
Note that if you are using a dark shine on a light layer, you may want to use the Multiply blending mode instead.
That's it! Play the project and enjoy the light sweep animation.