I got it !
This way is far more easy. Here are the steps :
– below your main layer, put a solid with the color you want your letters to turn into (for me it was a red solid)
– use a “Color key effect” (it’s in Obsolete effects) on the layer you want to transform the letters of
° with the eyedropper, pick the color you want to make transparent (the color of the letters…)
°adjust the Tolerance and Feather values to achieve the best result
You’ll see the color of your solid replacing the original color of your letters 🙂
Now if you want the effect to occur as you read the text, for example :
– Add a mask with the pen tool, covering precisely your first line of text
– Twirl down the “Color key” effect to reveal the Compositing Options (in the timeline)
°Hit the + button and select your mask : the effect will apply only to your masked area
Last step : add keyframes to the “mask path” in your mask options
– you need keyframes at the start and a the end of your revealing effect, depending of how long you want it to last
– go to the first keyframe : click “form”, next to “mask path”
° then, just put something like “10” in the “right” value : the mask will deploy from 10 pixels wide (from the first keyframe), to its final size (at the last keyframe).
I attach a screenshot of the effect running.
Perhaps there was an even simpliest way to achieve this, but I can’t figure one^^’
I think the effect could be improved using a Trapcode effect on the solid, to have some glow or light rays, I don’t know.
Have a nice weekend ! 😄