This tutorial follows on from our other video, Using Poliigon textures in 3DS Max with Corona.
High quality textures are just the first part of creating realistic, believable materials. In the real world nothing is clean, even the most sterile environment will have imperfections and it's important to replicate that when creating realistic renders.
Create a new image texture node and load in the smudges texture (use the black smudges on a white background), be sure to click on override in the color space options so the gamma is set to 1.0.
Add in a Composite node and feed in the original gloss texture into the top input and the smudges into the bottom input. Finally feed the output of the Composite into the Refl. Gloss input of the Corona Shader.
Adjust scaling via the smudges texture node and strength via the composite node.
Create a new image texture node and load in the scratches texture (use the greyscale black scratches on a white background)), be sure to click on override in the color space options so the gamma is set to 1.0.
Connect the scratches texture to the additional bump input of the CoronaNormal node which should already be present.
Adjust scaling via the texture node and strength via the CoronaNormal node.