Region rendering would be beneficial if you would want to render a certain part of the image. Specially for animations from still images, where people are moving in only a part of the image.
Volumetric Visibility Option or Volumetric Feature in Vantage
I am an Interior Architecht I use vantage a lot. I had a lot of trouble making images of dust or fire and smoke in indoor and outdoor animations. the fact that these features can be seen or done in vantage means that I will not need another progra...