Using ORM - TehMerow/PBR_Bake_Tools GitHub Wiki

This add-on has the ability to bake ORM textures

You might be wondering what an ORM is and what it stands for

ORM is a texture format that is short for Occlusion Roughness Metalness and is useful for storing those 3 greyscale channels in one texture by putting each in in a separate color channel. Red for Occlusion, Green for Roughness and Blue for Metallness. This is useful because it leads to a smaller file size than 3 separate textures and allows less textures to be stored in RAM. This trick is used commonly in the video games.

However, Blender doesn't really have support for ORM textures out of the box and Node Wrangler at this time doesn't know how to deal with it either.

This is a quite simple fix.

When importing a ORM texture, add a 'Separate RGB' node and connect the output of the ORM texture to the Input. Add a MixRGB node, change the type to Multiply and connect the base color into first color input and R output on the separate RGB node to the second color input

R output goes to the Roughness input of the Principled BSDF node and B goes to the Metalness input of the Principled BSDF node