I am wondering how can I combine 2 NetworkMaterial in KtoA. Basically, I created 2 networkMaterial, a snow and a ice, now I want to combine both material together as one network material. Something like mix_shader node, but mix_networkMaterial.
You must mix them tggether in the shader network, and then output a single network material. Katana itself doesn't support any concept of merging materials like that, so you have to use a mix/layer/etc in the shader network itself
Note that you can take just a part of a shader network and output it to a network material node, while continuing the shader network by connecting it to more shader nodes (eventually outputting to another network material node), if you wanted to keep individual layers of shading separate as an option.