Wow, so you're working on a 3-space graph layout plugin? I'm thrilled to hear that--it will be a great addition to the Gephi platform.
I'm not sure if you're asking how to build a plug-in in general or what sort of design for a plugin might work well.
If you're looking for some general info on how to design and share plugins with the Gephi community, you can check this out:https://marketplace.gephi.org/faq/
If you're looking for what sort of functionality might work well for a 3-space layout algorithm, I can offer a few suggestions.
First, there used to be a very nice 3-space graph layout plugin, but I think it has since disappeared from the Gephi plugin marketplace. If you can find it, that might be a helpful place to start. I think it was called "Transformation" or something like that.
That plugin could do the following:
PLACE NODES IN 3-SPACE: Set the x, y, and z values for a graph based on any numeric column in the Data Lab's nodes table. Of course, a user didn't have to populate all three coordinates; the user could choose to populate whichever of the 3 coordinates that he or she wanted.
ROTATE A GRAPH AROUND ANY AXIS: The user could put a value (in degrees) in the layout dialog for rotating around the x, y, and z axes. When the user clicked "run" the plugin would rotate the graph accordingly. This can produce a really cool effect. For example, a user could enter "5" for the Rotate(Y) value and "0.2" for the Rotate(X) value and then keep hitting the "run" button and the graph would rotate in 3-space. This can produce results that are visually stunning.
SKEW A GRAPH IN 3-SPACE: The user could enter a number that would serve as a coefficient for skewing the graph in the x, y, and z axes. This, too, can produce some cool effects.
Oh, I just did a Google search on the plugin and I think this the old plugin that I mentioned above:https://gephi.org/plugins/geometrictransformation/
Maybe there's a way to find it and use it as guidance.
Thanks, HamPlanet. Best of luck in your project. It's a great idea and I hope you share your plugin with the Gephi community.
P.S. Your English is quite good!