Today a colleague (Jani Ylinen, a graphics designer who knows everything about Rhino and Maya) from Nokia helped me out with Rhino a bit. So here is what I learned today.
If there is need to make 2D cross sections of for example of the fuselage, it can be done as follows:
1. Create a rectangular surface.
2. Make rectangular array of it. Adjust proper step to proper direction and use appropriate number of copies. E.g. 100 cross sections, one per each 5 cm for example.
3. Then choose Object intersection. Select all items (the rectangles plus the 3D model that you are going to cut apart)
4. Hit enter and wait that iRhino does the processing. It is slow in the current alpha-version.
5. Move the cross sections to another layer
6. Hide the 3D object layer
7. And you have cross sections. You can export these to in dxf format to for example to Qcad and process them further there. E.g. you can plot them to paper. Printing from Rhino is possible as well, but it prints the zoom level of a view that is currently present, and the scale you get can be about anything (not something that you can repeat for each model and do exactly the same scale drawings on paper each time, does not succeed with Rhino printing capabilities).
Jani also showed how to do radius. Select radius tool, select surfaces and type the radius and hit enter. Magically the radius appears to the piece with amazing accuracy.
There is also a silhouette function that makes a 2D projection out of the wireframe. You can propably utilize that in a 2D Cad, e.g. QCad (or Autocad if you are wealthy enough to have the overpriced licence to that outdated software).
I learned today that actually Rhino can be used for technical drawing without using more traditional technical drawing programs. You need to keep your model history with layers manually (if you change some cross section for example, you need to loft again), but with some work, it seems to be all you need. Also measurements can be handled, but you need to maintain them manually too, if you change some shape, you may need to update your dimension as well. With cutaways with the cross sections and the silhouette function, it seems that all sorts of technical drawing can be done with Rhino. It is different and some things are very manual, but on the other hand, as a bonus, the 3D side is so blazingly good that there is nothing that compares with it in user friendliness and expressivity. You can really create with this tool and about everything is there, you just need to discover all the functions.
Seems like the price-value ratio of Rhino is exceptionally good. With one thousand you can get so nice tool that it actually is better and especially a lot easier to use than overpriced Autodesk tools. This is how the design is done in the future for sure.
I am also downloading the Maya personal edition for Mac now. I plan to try it out for rendering models modeled in iRhino.
Many thanks to Jani for guidance with graphics software. It is very much fun to learn new things.