The diagonal planes are there, but not used very often. We did think we would need them more, but it turns out that we generally do nicely without. So they are there for the special occasions, and can be used for more detailed writing or research, but even if I was (one of the persons) who asked for them a lot, I now see that they are not as neccessary as I, for one, thought before. My personal suggestion is that you just mention the fact that these palnes do exist in actual signing, but that they do not seem to be neccessary for efficient writing or reading, and that you choose not to include them in your project at the present time. That way, you show that you are aware of the phenomenon, that you have considered including these planes, and your reasons for not doing this (not neccessary, more complicated program, both for development and use)
I'm on the verge of my thesis writing up for my research, and the Direct SignWritng system development is forming its shape. Some systematic testing and evaluations are conducting tensely recently to summarise my work.
While our developed system's reference planes are divided into two, the wall and floor plane, we are aware there is another reference plane which is the 'diagonal plane', although it is seldom to see such plane in the SW literature. Is that possible to know how import or how often this plane is used in SW?
The reason I'm asking is that I'm personally reluctant to implement it in my system by now, for it requires huge amount of work to do and will put off my deadline greatly. My intention is to demonstrate these two developed reference planes only at this stage to show the capability of the system, for we are not a company to produce a product after all, which should cover all functions.
I would like to hear other people's opinion in terms of how important the 'diagonal plane' for SW as well.