I went through all materials, and it is quite clear that they are not optimized at all. That is perhaps on purpose. Every scene will get its own aesthetic, as leaving the materials as is has a few disadvantages. I guess there are as many adjustment variations as artists using these. Which is excellent, from my point of view.
When you look at bricks, they usually have a very dull surface, some have some crystal-like sprinkles in it, others have a clear coat over them (I grew up in a construction company, so this is just muscle-memory for me.)
The main idea is, if not wet, they are more or less dull on average. Now, please look at the material. Every single material has a metal layer and a Reflection layer established. Both are set to 100% roughness. Since this seems to be a default, it would be better to put those to zero, in the layer and roughness. Then go from there if at all. Why, because it increases the render-time enormously, and 100% roughness, twice is not what I think will suit most of the given materials.
Again, when it comes to textures (surfacing), there are many ideas all over the place. Fifteen years ago, we went through a lot of effort to convince everyone to render in linear light.
But that works only when the textures are well-calibrated. I have yet to see a texture library that gives you the Color temperature in which they were shot or developed. Nor is any mentioning of the gray-point (card) use.
I could go on for a day about this, or two if I must…
The point is, they are just suggestions or starting points always, nothing that is even remotely physical correct. Hence why everyone will do his/her very own thing with it.
This brings me back to my initial statement; these materials seem to be set as a starting point, not for direct use.
If you like to go with the 100% roughness in two channels, prepare for very long render-time. As the quality must be higher than in the Physical Render.
I would think that the bricks will look OK with the old and more often abandoned Specular Blinn [fake!]. For a decade, we have all trashed this option and evangelized everyone to use reflections only.
When I think how often I get that people render without Motion Blur because it takes so long, I ask myself, is it worth having “Saving Private Ryan” film stutter aesthetic, but an ego pleasing “real” specular highlight?
As usual, it is an artist’s call. I’m the last one who claims that I found the one and only settings. So, please evaluate whatever tips you got with what pushes the mood forward and enables other qualities. BTW, often a lot of motion blur and /or DOF/Bokeh eats a lot of noise.
I’m not sure if I would bake noise reduction into the rendering.
Please check all layers about the roughness value, and if you want to keep it, set the quality in the Physical Render accordingly. Patrick went one time through all parameters of this in a series here on Cineversity.
Currently, sadly not online, fingers crossed it will be back soon.
I hope that helps
All the best
https://help.maxon.net/r23/en-us/Default.htm#html/MMATERIAL-ID_MATERIALGROUP_REFLECTION.html?TocPath=Material Manager|Material Properties / Material Editor|_____9