[pfranz]

I don't know if any of them are extremely easy to pick up. Any re-use between applications are the domain-specific parts (knowing about color space, UVs, shaders, and cameras) not the UI. Node based interfaces are pretty limiting. A lot of the power of these systems are things like having a Python runtime or text representations of scene files that you can find/replace. The other pro/power features are shortcut keys and templates, just like other apps like Lightroom or Avid.

Node based systems is a great pattern for certain things, but large scenes get unwieldy quick. Even if the project files are text, diffing with version control is useless. Profiling is often difficult--a pet peeve of mine when apps load all the whole scene file and often the geometry when you just want to change a parameter.

You can see node based systems "grow up" by adding variables or attribute references, which means your data isn't just flowing down the graph, but you have to track references in this new dimension. You then often see encapsulation (hda/otl, Gizmos), which can really help with re-use but create more limitations.