OpenRA

Is there any documents about software design, diagrams or any stuff may help understanding the code right way.
The code is so huge, and is really very good code. but I spent about 2 months till now, and still there are some classes' relationships not clear.
Any suggestions?

I usually use the features of MonoDevelop such as find references or go to declaration to navigate through the code. When in doubt I ask chrisf in #openra or we discuss problems via GitHub code comments. There are some very general outlines on the https://github.com/OpenRA/OpenRA/wiki/ but no documentation and very few source code comments. Everything in the class hierarchy is subject to change at any time. You should not work 2 months in secret and then send a giant patch, but send continuously small pull requests to the git repository to get your features merged.

Thanks @Cmd. Matt,
I did the same, navigating through the code, follow references, analyzing procedures and so on.
But what I supposed is that a such strongly designed code should be implemented based on some software engineering study or in the minimum some pattern design consideration.
Do you say there is not anything of that?

I added https://github.com/OpenRA/OpenRA/wiki/Traits in https://github.com/OpenRA/OpenRA/pull/2808 Hope this helps a bit.