To avoid having to wait for the render time in complex images, I have seen other Blender uses do something where inside the 3D view window, they placed a small frame over part of the image–and everything inside of that frame was rendered alone.
I’ve never known how to do this, but I want to learn. I’ve searched for tutorials or information all over here, on Google, etc… so hopefully someone can help me.
Thank you for reading this. Please help if you can.