How to add a 3D surface in Adobe Photoshop CC?

Question

3D

Below we have a screenshot in which we have a 3D character, but the bottom surface is made from a simple image (not a 3D layer).
How can I add a 3D surface with a grass texture and position it under other 3D objects?

Answer 1

This is not the first post with an attempt to use Photoshop for purposes not assigned to it.
Maybe it's better to take After Effects?