Is there a way to render only a selected portion of a scene? Maybe I just haven't caught on yet, but it comes to mind from my trials in Maya where you have the ability to select a smaller area of the scene inside the render window and then re-render just that small section. As an example, I've been testing rocks and plants in a scene, and if I've made a slight change it would be very convenient to select the area around that one object and quickly render that small section, instead of having to render the entire window again. Even nicer...you could select a section covering half the rock or plant, render that half, and easily see the difference your changes have made by comparing the new half to the previous half. It's a big help as well as a time saver.
I know you can zoom in on one object to crop out everything else, but the above is very convenient and offers some nice benefits.
Thanks.