Before 2.79 I used a dialectric node setup outlined by Andrew Price for PBR materials. This involved "reflectivity" maps among other maps, which I used, and many PBR texture maps include the reflectivity map. But I see no "reflectivity" value in the new Principled Shader. Where do I plug in this map? I know it's not roughness, because that's its own thing, and I know that the "specular" value probably isn't it, because I've heard multiple people say that that value isn't for when you're trying to do physically accurate shading; that it's not a PBR-related setting. I know there is some other PBR-related value I'm not using that affects reflections, because I plug in roughness and normal maps for very rough, dull materials, and they still look shiny.

Thanks for any help y'all can give!

  • $\begingroup$ if i remember correctly from blender gurus video, he says that the reflection map is not needed when using the principled shader because with the principled shader, the reflective data is in the color map $\endgroup$
    – kobe
    Apr 25 '19 at 17:28

Actually, it is the specular value input, specular is reflectivity. It's just that in some non PBR setups specular is a way of faking a reflected highlight without calulating actual reflections, and they called it specular. But in the principled shader specular means reflection and that's where you would put the reflection map, also sometimes called a specular map.

Play with the specular value and you'll see you can go from zero reflection to 100% mirror reflection. Roughness is basically your way of dulling down or polishing up the reflectivity, it's like a gloss value



This is from Blender guru.

He shows where is the reflections.

A short explanation of principled:

link: https://goo.gl/fgsyxN

enter image description here

  • 3
    $\begingroup$ It doesn't seem that he specifically addresses the PBR reflectivity parameter in the video. I just found that setting the roughness up to one pretty much gets rid of the shininess. Am I correct in concluding that any PBR texture pack that includes a reflectivity map has the roughness map not bright enough to do this, since the creator of that pack expects there to be a separate reflectivity parameter to crank down the actual reflectivity? If so, can the problem be solved by simply brightening the roughness map? $\endgroup$ Sep 17 '17 at 1:43
  • $\begingroup$ A glossy shader with a roughness of 1.0 is very close to a diffuse shader. A reflection map connected to this will effectively control the reflections over the mesh. $\endgroup$
    – sambler
    Sep 17 '17 at 4:21

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