Sure thing: - DISCLAIMER - Neither i, nor the good folks at Marmoset.co are responsible for anything that could happen to your computer as a result of using this shader. It is released "as is", with limited support. It will work with any existing content or materials you've created, and only changes the specular BRDF to…
Speaking of different models I finally got around to looking in the UE4 source for Oren-Nayar, and there's a nice file in the Shaders folder called BRDF.usf. It has a bunch of different models you can switch between for pretty much everything. For the diffuse model you can choose between Lambert(default), Burley, and…