Using Vertex colours to edit world position offset

In UE4 I am adding a simple grass wind to some foliage I made and have painted the bottom of the mesh a different colour to mask so it doesnt move and the rest does, however when I test the material the whole mesh moves, and when I test the vertex colours in the defuse slot it shows that they imported corrected and yet they are not working with the world position offset. My question is why isnt the vertex colours working for this and have I possibly overlooked something. Below is a screenshot of the material edit, its very basic what im doing for this yet cant understand why it wont work.

Did you ever solve this?

I believe so, thanks,

would you mind to explaining what the fault was or what your solution is?

Yeah I know right? I can try though as I managed to figure it out. I was looking at the rgb outs on the vertex color node as 256, 256, 256… Silly artist. They are float values 0.0 - > 1.0. Once you know your target target color mask value (the rgb float representation) you can use a series of “if” Nodes to compare the vertex color with your target. If nodes can check less than, equal to, or greater than float values. So you have to do his for each channel. Compare red against red, green to green, and blue to blue. Maybe there is a single node that does this but I couldn’t find it.