Simulate objects underwater

[peterekberg]

Can someone please tell me how to set up the project correctly for the tutorial "Simulate objects underwater".

I have read the instructions over and over again and can't manage to get the setup as displayed in the tutorial.

i always get two compositions Cass_Spa and Cass_Spa 2 and one folder Cass_Spa Layers. The instructions can not be complete I think or I am missing something obvious. A clear discription of this would be handy to understand what is happening when just importing the .psd files.

Thanks

Peter

[imeilfx]

Shortest and/or easiest for yo u will be to download project file that is avaliable on page with that tutorial and there you can see how it is made. https://helpx.adobe.com/after-effects/how-to/water-ripple-underwater-effect.html 

[peterekberg]

I got it right finally. But one question though. How am I supposed to know what layer to add the effects on? Why was not all effects added to the solid layer? Is there any logic that help me understand that?

[imeilfx]

You just have to know - that is the simplest answer. 
You have to learn After Effects basics to know that. I that particular effect/animation you need to use two layers - first layer with your exact footage (composition) and second one as a source of distortion (gray solid) - only that way it will work. If you f.eg. put Wave Wold (effect that generates waves) on your footage - it will become gray because that is how that effect works. That is why you need two layers. 

[Rick Gerard]

There are a lot of effects that have the option to reference other layers. Caustics is one of those. So is Displacement Map, Match Grain, 3D Fog and others. If the effect has the option to reference another layer:

 

Then to make that effect do its job you need to put the effect on another layer.  That tutorial could have been a little clearer. I would have renamed the Gray Solid to indicate what it is used for. Renaming layers becomes more important as compositions get more complex.

[peterekberg]

Thanks, this sentence actually made it more clear. : If the effect has the option to reference another layer