To anyone wanting to get this to work simply select a water plane and then use the paint tool. You can see in the drop down menu each rgb view and paint the shade of red or green you like. Look at the preview map with different planes in paint mode and red or green view selected to get an idea.
Anyway now i’ve had time to play around I have to say while the water effects are quite nice im not sure using vertex painting is ideal.
If you plan to use it for a big ocean I can’t see how this a good choice as it seems we’re expected to copy hundreds or even thousands of small planes with many triangles each. Scaling doesn’t work with waves and the shore line gets stretched.
I might try a custom mesh in blender at some point but i doubt it will work as expected?
It’s also tricky to get good results with multiple planes and painting plus the vertex resolution is quite low so it looks blocky on the wet sand.
Can’t complain too much for free but it would have been nice if the creator had made a quick guide for everyone and a large ocean option. Thanks!