First time I used Unreal Engine 4(Game engine) for my professional task. It was a huge game changer!!! Client overseas was able to see whole scene of tens of houses, thousands of trees, many people, cars real time live, through skype and we worked together on designs of houses from sketches, on details.
Needless to say that client was so much satisfied and amazed with such opportunity. No waiting for pre renders, stages, etc. client actually could see whole process and take part in it. I was also pleased with process, as I would concentrate on actual scene without making a lot of images from stages for corrections/approval.
After Scene was ready, we choose 40 positions of shots and those were generated in seconds each in high resolution already post processed. This completed scene also makes possibility to make flight rough animations in no time compared to typical way of rendering. So it means that cost a lot cheaper for client and result is decent. Of course, particular images are far from photo realism and perfection, which could be achieved with greater budget/time. But it can be even better.
So contact me, if You want great, interactive, streaming result faster despite of scale of a project!