Yesterday I added new texture functionality to Model Viewer with obj files. Atrr Map, really this map is not native support in exporters but I added in mtl file attr_map string to define texture path.
This texture has RGBA layers. R = specular map, G = ambient occlusion map, B = height map, A = unused. In this screen shots you can see B layer running with one light function. The light position is in vec3(0.0, 100.0, 100.0) so in left and right side with height simulation you can see a few light too.
As you can see, there is no anti aliasing or anisotropic filtering.