Displacement mapping and Material nodes

Just Wondering if anyone knows why the displacement channel disappears from the “Map to” texture section of my material once it becomes part of a node tree i created.

let me elaborate, I created two nice materials including color maps and a very specific displacement map, so i wanted to mix the two, so i created a node tree, mixed both textures but i came to find that they where no longer displacing the geometry. so i reverted back to before i made the nodes and the displacement work as single materials but once i switched to nodes that channel disappears.

Has anyone experienced this before, or know that the “dis” channel is not available once the material is part of a node tree? any thoughts, comments or ideas are welcome.



partially solved my issue, i just created several vertex groups with the displace modifier on the geometry. applied the textures I planned to use and ended up with a end result that I’m happy with…

But still this does not answer my original question,

does anyone know if and why the “disp” channel disappears when a material is added to a node tree??
is that why there is a displace modifier?