RenderManager should handle the signals directly, instead of relayed by the RenderThread.
SceneObject::update and SceneObject::uniform should be left blank instead of =0, which enforces subclasses to implement it although not all of them need it.
{ should be in the same line of class DEFINITION. Although most coding styles are merely choices, this one is NOT as long as you are trying to use cscope. It's because cscope is not smart enough to separate class declarations and definitions, and appending { gives us a hint about this.
I don't like the design of RenderThread::renderMgr, but I won't change it unless we have time.
Do NOT use underscore as the prefix, names starting with have been reserved by C standard. m or suffix _ are both sane choices.
Some stuff that I'm not very satisfied.