Below are some of the tutorials I have written, currently all for an obscure piece of gaming software called Nolimits 2.

Nolimits 2 materials (part b1): Global texture coordinates

Learn how to use texture coordinate generation for terrain-covering objects like trenches and tunnels

Nolimits 2 materials (part a4): Specular Maps

how to make good specular maps and when to use them

Nolimits 2 materials (part a3): Emission Maps

access additional material registers using the NL2 custom shader core

Nolimits 2 materials (part a2): Texture sizing

How to choose sensible texture sizes for Nolimits 2 projects

Nolimits 2 materials (part a1): The specular model

How specular lighting works and how to select realistic values for your materials