[Bf-funboard] Cycles refresh annoyance

[Gatis Kurzemnieks]

Hello.

How hard would it be to make that cycles viewport preview render is not
re-rendered until some real changes are done in node editor. I mean - now
viewport is re-rendered every time I add new node that is not even
connected to anything.. and of course at that moment everything freezes and
the workflow is interrupted.

It would be super nice if i could add new nodes.. even make new complex
networks, but until they are connected to Material Output node - no
re-rendering occurs.

I feel that this fix would be appreciated by everyone and it should not be
so hard to implement.

Gatis