I'm trying to get a very basic viewport shader representation going for my redshift shaders, although this issue doesn't really have anything to do with redshift… I've added the Diffuse Texture Layers from the parameter interface and my diffuse texture loads fine, but the material is super shiny. I have added all the specular and various other related parameters, but it seems like the specular value doesn't work at all to lower the specular. I can increase the roughness to 1 and that works, but it's still showing specular, just very rough.  The Enable Specular checkbox also doesn't work, nor does the specular intensity slider. Turning off the specular component in the High Quality Lighting viewport options doesn't work either.

I started from this thread on the RS forums where someone made a nice HDA for the redshift shader to show in the viewport and I was trying to make my own basic version to learn about the openGL viewport stuff.

https://www.redshift3d.com/forums/viewthread/24071/P45/#151805 [www.redshift3d.com]