Parallax and Normal Mapping
These two effects are not too complicated and can really make the 3D scene look much much better. For a simple 2D texture, it can turn something like this :
To :
The effect simply consists of displacing the texture coordinates of the rendered texture depending on the angle at which the camera views the surface.
The best explanation I found from here : https://learnopengl.com/Advanced-Lighting/Parallax-Mapping