Flood Fill Failing?

StormyBA

Does anyone know what is causing this kind of effect with the flood fill node. This seems to happen with pretty much any hightmap I plug into the node but I can get some better results if I kill contrast in the height map but that is not ideal if you have more complex patterns. 

Ive tired messing with the contrast, forcing the input to 16bit few other bits and bobs too but not having to much luck with it. 

Currently running the DX10 engine and got a 1070. 

CheeseOnToast

You need to use a binary black / white input. Run a levels on it and increase the contrast. The flood fill node then needs to be plugged into one of the flood fill effects nodes (greyscale, colour etc.)

Finnn

In the past I had some problems with the flood fill node too. Cheese is right, you need complete black and white values. Also if you are working with tiles it is best, when they are "closed". The flood fill Algorithm is filling out every closed form on its own. 
Maybe this helps you to understand the way it works: