I am working on a logo for the company I currently work for, and the background to their logo is a script C.. I was wondering what I would have to do to have a streak of light paint the C, but only have the C left behind.
I'm very bad at explaining this, does that give you a basic idea atleast?
I will see if I can find a solid example, I have a rough draft more or less of what we want to do, its just one part that is holding me up.
Essentially I want it to be similar to a write on effect that comes on screen from the left side of the screen, once in the middle of the screen it begins to trace out the design and then exit on the right side, similar to the light presets, I want it to animate off, but leave the traced design animated on the screen in the middle.
I will see if I can find an example somewhere on the interweb
Well, I'm still learning Motion so I might be wrong.
But it seems as if this effect would be created in two layers. It's kind of a magic trick. You put the logo out there but transparent. Then you put something over it and when that "something" is gone, it's no longer transparent.
The top layer would be the light streak, created with a "sliding window" of write on behaviors.
Underneath, there is a layer with the "C" graphic to be left behind.
Start the animation with the opacity of the "C" graphic set to zero.
Tweak the light streak so that the beginning and end of the streak cover both ends of the logo at some point in the animation.
Keyframe the opacity to zero on the frame before that point and 100% on the exact frame where the logo is covered. As the light streak "writes off", it'll reveal the logo which was there all the time but transparent.
[Colin Heichman]"Keyframe the opacity to zero on the frame before that point and 100% on the exact frame where the logo is covered. As the light streak "writes off", it'll reveal the logo which was there all the time but transparent."
That's certainly one way of doing it, but you can also make the logo appear to write on rather than fade on, which is what I did in my example.
Quick'n'dirty way of doing it:
Step 1 - position and size your logo appropriately. I just used a letter "C" in a flowery font.
Step 2 - use the Bezier tool to draw a path from one side of the screen to the other, tracing the outline of the logo. Double-click on the final point so that it remains a line and not a filled shape. (I've made the background green on this grab so that you can see the Bezier shape path more easily).
Step 3 - select your Bezier line in the Layers list, go to the Shape tab of the Inspector, turn on Outline, set the brush type to Airbrush, and then crank up the brush width until the logo is completely covered. Add a Write On behaviour to the Bezier line.
Step 4 - add an image mask to the logo, then drag the Bezier line into the mask source well, ensuring that the mask source channel is set to Alpha and the mask blend mode to Add (it should default to these settings). Play the sequence and you should see the logo draw itself into existence. The Write On behaviour is animating the Bezier line to create an animated mask that reveals the logo.
Step 5 - duplicate the Bezier line, drag it above the logo layer, turn on its visibility checkbox and delete the Write On behaviour. Go to the Shape tab of the Inspector and in Shape Styles, select one of the light streaks. Adjust the brush width to taste. The light streak will animate across the full width of the screen, and appear to write the logo on as it passes.
Your Layers stack should look something like this: