One of the typical problems with diagramming Origami, is representing some of the various shapes in 3D space. CAD programs can do this, but the variety of shapes complicates the process. So, the current diagramming Origami standards require a little experience both to use and to follow. And, of course, CPs require even more experience, and maybe a different type of mental wiring.
Having said that, these 3D Origami models are a special case of modular origami, where the unit of design is a triangular piece. Like Engineer design, as suggested by melba, if you are good with engineering modeling and CAD, you might easily apply those tools to 3D diagrams.
I imagine that there are some free CAD modeling tools available, there may even be some XML languages and VRML-like tools that would help.
Of course, if you don't know CAD, then don't read this post
- Hank Simon