Global Shader Mix or Add Shader

Intro: I figured a cool way to create shader based mist effects to renders by using camera data node. Then I realized that having this to every single one of my shaders in whole scene is extremely slow thing to do. So I realized that there could be other situations too where you would like to want do add the same mix or add shader effect to all of the shaders you have. For example in some toon shading scenes you would like to have for example some light effects to all models, or you could have the whole toon effect as a global shader mix effect.

Suggestion:

• My suggestion is that we should have in "world properties" or "scene properties", or "view layer" a new "global mix material" tab.

• There you could create a new material that will be added as a "mix node" to every single one of your existing materials and your new global material would be then mixed as a branch to those.

• You should also be able to control the factor of this new global mix.

• Alternatively you should be able to have "add shader" node to all of your materials. Or both, or multiple of those, maybe as a node group.

• There should be a list that allows you to exclude this new mix node from the materials you have added to that list.

• Behind the curtain this would obviously work in a similar way as the material override from "view layer", but instead of overriding every material, it would add new nodes to the existing materials.

• When you use this setting, you should have the new nodes visible in all the materials as some sort of a "link node" or node group, that would allow you to change the settings.

• You should also be able to make this node to be individual node group for the selected material. If you did that, it would automatically add the material for what you did it, to the list of excluded materials in the global settings.