You need to add some animated masks. It is a bit tedious but easily done.
I take it I just create a mask that adds a bit of text every frame or so using that?
No, I add a solid and add masks to the solid that fix the overlays and use the solid as a track matte. If you use a a complementary color and set the blend mode to screen you can see through the track matte to help draw the masks. I usually make the animation run slower than I want it then nest the write on effect and use time remapping to set the final speed.
so I would still use the path/stroke, and just use the solid to block out the problem areas? sorry Rick, I'm really new to this. Thanks for your help! :-)
Take a close look at this project. It's part of an upcoming tutorial on animating text and masks. Maybe the project will help. It's saved as a CC.
Note: Dropbox will probably add a .txt extension to the file so just remove it so it just says ScriptWriteOnText_CC.aep and it should open just fine.
The procedure was to create a text layer, then convert the text to a shape, then add a solid with stroke below the shape. I then animated the end of the Stroke with stroke set to On Transparent. I used the shape layer as a track matte to trim the stroke to the exact shape of the text converted to shape layer. I then added and animated the masks on the track matte layer. Each mask was changed to subtract and as I scrubbed through the timeline I added as many masks as I needed to clean up the crossing lines.
There are many ways to do this. You could split the layer at the cross over, work the other way around, use Paint, but the idea is always the same and it's tedious, especially if there are a lot of crossing points. You could even create your text layers in Illustrator, convert the text to outlines, then divide up the segments of the letters and sequence them in After Effects.
The faster you make the animation the easier it is to hide the crossing problems. For example, it only takes me about 3 seconds to sign my full name and with a signature that is that fast you could get away with a lot.
Thanks for making your project publicly available for download. I've taken a look at it and figured out how to create masks to do the same in my project. I'd love to hear about your entire process though, have you finished the tutorial and is it available somewhere so I can see it?