Mission start. The aircraft had just been unveiled the previous day and some photo came out. There happened to be some with the right angles. I relied on these photos instead of other 3-views circulating on the internet, hopefully suffering less inaccuracy from other's interpretation this way. - Those people have no better information than I do.
First off is the initial shaping. Using lines to create a 3D outline from the photos, to give an idea of the shape of the aircraft. I used the same method for J-10 and turned out to be quite useful for a subject without cross-section diagrams (in this case, the subject lacks more than just that...)
The info from the photos have been extracted, and nothing more quantitative can come from looking at the photos. (unless someone happened to have a certain agency's software to analyse lighting and shadows...)
Detailed lines as cross-sections. I drew these directly, although another way is to create a preliminary surface and go from there. The J-20's shape is relatively simple, so drawing directly reduces the amount of work needed. (Don't tell me about J-10, I've had horrifying experiences with that one...)
Continuing towards the rear
There are photos of the gear bays, but I didn't dare to go more detailed than this.
The cockpit configuration is classified... I'll leave the detailing to serious builders.
Internal support structures. It did take 4 days...
Post-processing work on the supports, another 3 days... I did try a novel method to hopefully make the fit better, but it could make things worse so I hope Wind can bring me the good news!
Unfolding the skin, post-processing and the like. It's these things which take the majority of the time to do...
Colouring in Photoshop. Took this long to give the parts plain colour. I couldn't imagine how much work went into GPM's weathering effects... Or I'm just not good enough with Photoshop!
...And that's it. Now let's wait patiently for the testbuild...