..thanks to AC member Chuky. The file shader_filter_list.txt acts like a "ban list" for the shaders . So in order to see one shader that is not visible by default, just open assettocorsa\sdk\editor\system\cfg\shader_filter_list.txt and remove the line with the name of the shader you are looking for. Example: remove the line that says ksMultilayer_frenel_nm, so you can access it in the editor. You can see all the available shader files in shaders directory. NOTE: Use at own risk ! If the shaders were not visible by default, one might think that Kunos did this on purpose, in order to encourage the use of only the "safe" shaders. No official communication yet.