The statistics (total shaders, keywords count, etc.) show in Build View is accurate because this data is collected from the build. The Project View only shows data based on the shader files found in your project (it does not include hidden shaders).
“Total Shaders”: the number of files with .shader extension found in the project.
“With Keywords”: number of shaders that use at least one keyword.
“Used Keywords”: the total number of enabled keywords that count towards the Unity limit.
When one or more keywords have been disabled by Shader Control, it will show the current enabled keywords vs the original amount. In the picture above, the original total keywords is 3 and one keyword has been disabled using Shader Control hence it shows “2 of 3”.
“Actual Variants”: the total number of shader variants (different compilations) that are generated by Unity according to the keywords permutations.
The “Clean All Materials” button disables any keyword stored in any material that’s also disabled in the shader source file.
When you disable a keyword using Shader Control and press Save, it does two things:
- Modifies the shader and comment out the keyword so it does not generate shader variants.
- Disables that keyword from any material that might be using it.
The button “Clean All Materials” just repeat the second step but does this for all materials in the project. It takes every material and examines the corresponding shader for any referenced keyword in that material. If that keyword is disabled in the shader source code, then it’s also removed from the material. Usually this step is not needed but pressing the button is harmless and ensures that there’re not disabled keywords set on the materials of the project that could be set by scripts.