Adding distortion to reflections

[Kagemao]

Hi gang,

Am still fiddling around making stuff (hopefully I can make something good enough to put up on Share!) and today's goal was a wet rock floor material with cracks.  Quite happy with my progress, but what I need to do to perfect it is to add a little distortion to the reflections in the water.

Can anyone give me some advice?  Intend to use in UE4.

Current Progress: https://gyazo.com/d3b4ecf8e1a773e53673667cc4eae8e5

[Nicolas Wirrmann]

Try to put a Perlin noise in the height corresponding to the water part. Lower the perlin height using a level or the "histogram range" node.

[Kagemao]

Hi Nicolas and thanks for the response.  I'm not very experienced with the height channel and I'm really not sure if I've done this right as I'm not seeing any distortion in the 'water' reflections still. 

Would someone be able to take a look and see if I'm doing it right?  Height channel is really not something I've ever messed with before.

[Vincent Gault]

I used it to use some distostortion on windows :
https://youtu.be/aJySbq7ec6k?t=6m4s

[Kagemao]

Ah, right!  I've been trying to use a height output when it's a height map being blended in with the normal.  That vid is brilliant, ty Vincent.  Wish me luck tonight when I have a play with it.