The Output nodes can build custom Node Graphs. Figure 1 shows a custom Node Graph that contains two Texture In nodes and a Texture Out node where the incoming texture maps are processed and mixed before the result is output . This output is available when you're navigating out of the custom Node Graph and up to the top level of the OctaneRender® material (Figure 2).
Figure 1: A Medium Out node is added to a custom Node Graph
Figure 2: The custom Node Graph now has an available Texture Out output pin