I have been looking for graphics engines that aren't game engines but also do not offload most of the work (matrices, z-buffer, etc) onto me. Ogre seems to be about what I am looking for, but I am wondering about differences between Ogre and Ogre-Next in terms of what you actually put into a program. For instance: On the "What version to choose?" page it compares Ogre's "Toolbox" approach vs Ogre-Next's "Framework" approach. But what does that actually mean? I am also confused as to how I can "choose the amount of worker threads". Does that mean GPU threads?
Also- I am fairly new to high-level graphics. I have been writing a simple 3d renderer using the painter's algorithm but I am lost on stuff like "RTSS" "PBS" "HLMS".
Guidance is appreciated!