Render Specific part of a scene... Is it Possible?

[saeedsh]

Dear All CGArchitects,

 

I have a question about V-Ray for Rhino 3.6...

 

So I've made a render that took nearly 12 hours but then realized that there was a tiny little detail 'Object' missing in the scene... so I started searching for a way to render that specific part of the scene and then blend it in photoshop...

for example, if a have a rendered image of 5000px × 2500px and the missing object is only in 800px × 400px of the whole image... would it be possible to only select an area and make the software render that part only?

 

 

or if there is another common way of fixing this problem please let me know

 

Much Appreciated