The Multi-Shader Editor is a way to rapidly make changes to a large number of shaders all at once. It is similar in spirit to the built-in “Master Light” dialog box, and works similarly: In the Assembly room, you first select the shaders that you wish to edit using the Shaders tab. You then invoke the command and the dialog opens. For each channel that you choose, you can then build up the sub-shader that you wish to use.
There are some important limitations:
This only works for standard Multi-Channel shaders: NOT terrain, layer, hair, or multi-channel mixer.
Not every sub-shader will work inside the dialog. Some shaders “know” about the shader room and assume that the shader room’s features
will be available.
Saving and loading shader presets does NOT work, for the same reason: the Carrara facility for saving and loading presets assumes that you are in the shader room, and attempts to update the nonexistant preview window, causing an error.