Friday, April 17, 2009

First Steps Towards a Multi Editor 3D

Some days ago I 3d-fied the UML 2 Tools Diagram Editors. Well, a single 2D editor in 3D is funny but not really thrilling. You may ask: "Why should I use a 2D editor in 3D?" And I agree with you. The idea behind GEF3D is to enable multi model or multi diagram editing (this is why I started the GEF3D project). I strongly believe that "raising the level of abstraction" as promoted by all these model-driven approaches requires good tools. What does "good" mean in that context? Many models are edited graphically*, and using different levels of abstraction means using different models, that is diagrams. Also, using different (architectural) view points means using different models or diagrams. And all these models are somehow related! But these relationships usually aren't visualized. Too often, the best thing you get is a (EMF generated) tree editor. The GMF mapping editor is a typical example. IMHO a good tool would be a tool enabling graphical notations throughout the development process. And this is what GEF3D is all about. By 3d-fying existing GEF or GMF based editors, it is possible to reuse existing code and, from the user's perspective, existing and well-known graphical notations. This is also a principle of GEF3D: Enable exiting editors to be reused in 3D. Nobody wants to write new 3D-enabled editors when there are 2D editors already available, and no user wants to learn a new 3D-like notion of the UML. The next step is to open several 2D diagrams in a single 3D scene. Actually this is working for quite some time, an example application is published in [1]. This application was more a design study or proof of concept, I 3d-fied an elder version of the TOPCASED UML editor (which is GEF based). With the 3d-fied UML2 Tools editors, I was optimistic to create a UML Tools multi editor as well. Frankly, I was very much surprised how easy that was! The example code is part of the UML2 tools example found in the GEF3D SVN. I created a video demonstrating the multi editor. Have fun! (Sorry for the bad quality, it's my first video I uploaded to YouTube) Watch the video at YouTube A multi editor certainly is only the foundation for real-world (MDD) applications. Opening multiple editors in a single 3D scene enables the visualization of inter-model (or inter-diagram) relations such as transformation traces [1], inter-package dependencies, model-differences, manual mappings and so on. While the demo sounds promising, there are a lot of problems and known bugs I don't want to keep secret. There are some problems with feedback figures, text editing is not working as expected, there are problems with rotated planes (yes, actually the planes can be positioned every where in the 3D scene), currently it isn't possible to simply move an element from one diagram to another and so on. The example is only the first step, and we are working for solving the known issues.
J. v. Pilgrim and B. Vanhooff and I. Schulz-Gerlach and Y. Berbers: Constructing and Visualizing Transformation Chains. In: ECMDA-FA 2008, Berlin, Germany, June 9-13, Proceedings, LNCS 5095, pp 17--32, Springer-Verlag, 2008. URL:

*For non-graphical models, XText is a wonderful tool. Combining text and graphical models certainly is a challenge for future research ;-)