I am using Sketchup Pro 2020 and Vray Next (still in trial period), and I am trying to get displacement to work correctly, specifically to create a lap siding material.
To experiment with this and other features, I simply started a new model with a couple boxes extruded. I made one box a component and the other I left a stand alone object.
To create this material, I have tried using a default wood plank material and also a generic material with a simple diffuse color. I then configured a gradient black to white texture, rotated the texture placement to horizontal and set the repeat value to 6 (to match the wood planks bitmap). I then added a displacement attribute, and slotted the gradient texture to it.
The problem I am having is the preview pane (wall close-up) shows the displacement correctly (albeit with some distortions in the corner edge), however it renders flat in the VRFB. I have tried applying the texture to just the component, then to all faces inside the component. I have tried reversing faces with no luck. Also tried increasing the amount, using 2d displacement, and normal displacement. The displacement switches in the material and settings are both on.