I did not mean to imply that Graph Builder is limited to just two variables. But visualizing this function would require some clear thinking about what you wanted to show and how you wanted to show it. I agree that GB can bring in more than two variables through different roles.
Also using the grouping and overlay roles limits the display to the levels in the column, so you would also have to build the data table more carefully to get the groups you want.
Use the DOE > Classical > Full Factorial design platform. You can ignore or delete the meta-data that is created, too. You won't need it since you are not fitting empirical data.
I understand -- I think I was mostly interested in knowing *how* to build the data table if I knew what levels I wanted for each of the inputs. Basically, is there an easy way to build a full-factorial-matrix data table given a min, increment, and max value for each variable?