Substance Graphs are the main type of Graph created in Substance Designer. Their purpose is to generate and process 2D image data that is not constrained to a set resolution, color or shape. They are meant as extremely versatile image-processing and generation tools, not just static, pre-set results.
The results can be in the form of a simple black-and-white pattern, a filter that only runs on other images and doesn't generate content by itself, or even a full-fledged procedural material with multiple channels.
Substance Graphs are the most widely supported type of Graph, and can be exported and used in a plethora of different workflows.
Below you can find some typical examples of common usecases.
A simple mask shape for a decal is created by generating a piece of text and a disc shape, extracting the edge from the disc and the finally blending them together before setting them as final output.
The Text with the number, or the thickness of the edge can be exposed externally to make this a more dynamic graph.
The contrast values set in the Histogram can be exposed, making this a simple but useful filter in combination with the dynamic Input slot.
A more complicated graph blends two Base Materials. One Base material is kept simple, the other uses some custom inputs to add interest. A Mask is used to determine which of the two materials appear where before being set as final outputs.
This example makes use of Link Creation Modes to simplify using multiple links.