Beside Scene Nodes Cinema 4D also offers nodes for the creation of materials. Many of the nodes that are available to create Standard/Physical material setups can be used within Scene Nodes as well.
A key concept needed here is the shading context, which obviously the Scene Nodes don’t have. It can be synthesized though since what is needed from it are mostly only the UVs for the shadeing node evaluation.
The below example uses a well known displacement map ear.exr, please replace it with any other displacement map you have, you will need to adjust the type of Displacement according to your map, just like you would in a material.
The same method can be used to get color information from a bitmap or anything else. Also the shading setup can be pretty complex if you need it, including layering etc.