You could already use 3D rendering software to do that. Zoom around in it, move or change the light sources, render from different angles. E.g. Daz Studio is free. But then you need 3D models of the structures, and if you want to actually construct those models it's quite a bit of work.
Sketchup is also free, and VERY easy to use.
As an example, when discussing plans to build a new house in the place where the last one burned down last winter, I made it as easy as I could on the contractor. I did a 3D rendering of the house we wanted in Sketchup, went into Google Earth and grabbed imagery of the land, placed it in the proper position, added some trees from the 3D Warehouse (basically a HUGE collection of free Sketchup models), added a few "textures" (color patterns on surfaces), and took sceenshots to send to him to illustrate any points we were discussing.
A 3 bedroom, 2 bath, 1920 sq. ft. house, on its proper footprint, with nearby trees that had to be chopped down or avoided, along with location of the well, the driveway, various outbuildings, etc..... maybe an hour and a half. Granted, I have been using it for a few years, and like anything else it gets faster and easier with practice, but still...
A castle is a huge and complex collection of structures, so that would take a while. But getting the sight lines right for the bar fight that's about to happen? You can build and furnish the local bar in under an hour, with practice.
Note: I SUCK CANAL WATER as an artist. Yes, it's *that* easy.
To be sure, it's probably not worth the trouble except in cases of:
1. Very simple structures, and/or
2. Places the party will return to over and over.