2015-08-21 RoughnessMap or GlossinessMap/SmooothnessMap PBR RoughnessMap group (0.0 smooth, 1.0 : rough) Unreal Engine 4 https://docs.unrealengine.com/latest/INT/Engine/Rendering/Materials/PhysicallyBased/index.html Substance https://www.allegorithmic.com/system/files/software/download/build/PBR_Guide_Vol.1.pdf https://www.allegorithmic.com/system/files/software/download/build/PBR_Guide_Vol.2.pdf Walt Disney Animation Studio http://blog.selfshadow.com/publications/s2012-shading-course/burley/s2012_pbs_disney_brdf_notes_v3.pdf Pixar http://blog.selfshadow.com/publications/s2013-shading-course/pixar/s2013_pbs_pixar_slides.pdf GlossinessMap/SmoothnessMap group ( 0.0 : rough, 1.0 : smooth ) Unity5 http://blogs.unity3d.com/jp/2015/02/18/working-with-physically-based-shading-a-practical-approach/ Marmoset Toolbag 2 http://www.marmoset.co/toolbag/learn/pbr-practice FrostBite http://www.frostbite.com/2014/11/moving-frostbite-to-pbr/