@LuLima - I'm so sorry that I've only just seen this! The basic set-up for making a Master material is to create a new Material and plug any diffuse texture into the 'Base Color' slot. Right-clicking this Texture box will give you the option to 'Convert to Parameter'. What this will do after you've named the Parameter is…
I forgot to mention! All textures in the scene are 512 or smaller, with most of them tiling. The main texture I used besides the tiling diffuse and height maps was a 512 Utility Texture I've made for various effects: Red Channel - Contains a Render Clouds map generated in Photoshop. Green Channel - Contains a Noise map.…