Recently I've purchased a number of PBR materials as I loved the look they had. Each set has an ambient occlusion, base color, height, normal and roughness map. Through trial and error I somewhat figured how to use them, yet I can't replicate the same look from the vendor examples.

It is a limitation of the Poser engine? or I am doing this wrong? I'm currently doing this

Ambient occlusion > diffuse value and specular value

Base color > diffuse color

Height > displacement

Normal > gradient bump

Roughness > bump

In Poser, Ambient Occlusion is not necessary unless you really want to accent a particular region on the material. It is more of a game development feature. Most probably the vendor used an HDRI as the light source. Which node are you using for rendering, Cycles, Physical Surface, or PrincipledBSDF?

Ah, I am using 2D textures hooked to PoserSurface. Perhaps that's where my problem is? I'm relatively new to poser.

There is nothing wrong with attempting to use the PoserSurface to use SuperFly rendering, it is convenient and easy. However, to really take advantage of the SuperFly features you should explore Cycles or Physical Surface nodes to better render realism and realism response.

Thank you, I will play around with those! :)

Not sure how well PBR works with Firefly. If you would like to experiment in Superfly below settings work ok for me. Note Displacement maps in Superfly work on existing mesh so unless you are using a very dense mesh this map will not be very effective. Its important to set the correct gamma correction for each map, I've marked them as GC below.

Thank you! this helped so much!

Thanks IronSoul, very useful. Are there any known tweaks that reduce render times when using PBR materials in Poser 11 or 12?

I find the above works ok in most situations, the problems start when adding opacity to complex overlapping geometries like hair.

A simple non refracting transparancy for eye surface and thin glass

Opacity example (eg billboards) - Opactity/Transparancy mask is not apply to spec map so its necessary to mask too.

parkdalegardener pointed out here that there's a set of templates showing how to connect PBR maps to a Poser Physical Surface node in the Materials library

Using Ironsoul's suggestion gave me much better results that any of my previous attempts. I will have to purchase more sets :P