Hi all!

I'm having trouble trying to work out how to do a certain effect in Maya (and After Effects, as I assume there'll be some compositing involved). I want to have a character in a completely black room, and when they take a step forward, a ripple effect comes from where their foot hits the floor, revealing the floor texture.

Here's a really quick render I did in AE to show you what I mean.

The idea is sort of inspired by Avatar: The Last Airbender and how Toph uses earth bending to see.

The effect is simple enough to do in AE just on a flat plane as you can see from the video, but I'd like the footsteps to also reveal nearby objects, such as a table or chair. Another shot I want to do is have the character touch another character's face, their nose for example, and then the ripple to follow the contours of their face.

The only way I can think to do something like this is to render out a z depth pass, and use it as a luma track matte in AE. The problem with this is that it will always reveal from the part of the face closest to the camera, instead of the part where the character's finger touches them.

You can see a similar effect to what I'm trying to achieve in some video games where the player presses a button and a pulse comes out of the player character, revealing nearby enemies - like an echolocation ability. Here is an example.

I hope that all makes sense. If anyone can help me figure this out I'd be most grateful!