Level Creation Process Explanation

For weeks now I've been recreating the first stage from Rush 2049, I've mentioned the process I've been using but not to any detail. Here is a little more in-depth look at the entire process I'm using for the entire stage, in case anyone looking back at this is curious about my methodologies.

So, it all begins with a piece of software called NinjaRipper, this program has been around for ages and is still used by hobbyists to extract models from modern titles. I've never used it before but have heard of it and figured I would see if it would work for my purposes.

The program works by manipulating the target game's runtime dll, once in game it is then able to take a 'screenshot' and extrapolates any 3D information in the current scene and exports it as an editable object file. While its results are hit and miss, it does work. In my case, it created the models I needed alas without textures and with obscurities.
I mentioned that a screenshot is created from the current scene, this in affect uses the in-game camera to gather information. As a result, any angles or FOV (field of view) is also captured, resulting in obscured models, usually with a slant on everything.

The result is something like in the image above. If you look at the top-right viewport, you can see all the edges are slanted to the right. Not only that, but many objects are duplicated more than once, so each building usually has a few copies on top of one another. Because of this, the model in its current state is unusable as a straight translation into my project and for optimisations purposes too.
However, it does serve as a good reference for re-creating the entire stage, as it shows objects beyond any in-game boundaries that I wouldn't usually be able to see.

With this reference model I can then create a white box stage by creating primitives on top of parts on this reference and gradually delete parts from this rip as I go along, creating a clean version.

This image is taken from the exact same perspective as the previous one, as you can see part of the map has been re-created and is much easier to view / navigate. It is also optimised with hidden faces removed and can be imported into Unity in its entirety without any issues:

By using the emulator for the original game (which I own) I can see what tiny details should look like in-game and recreate them using everything I've done previously. 
For example, the next area I'm working on has a tiny animated model of a tram, using the original rip as a reference I can create little things side-by-side.

Finally, once the entire stage has been white-boxed I can then texture everything! Thankfully a lot of the models are buildings which don’t require any intricate UV unwrapping.

*EDIT:

In addition to this method, another software called 3D Ripper DX also works, however both work in different ways.
Depending on settings, NinjaRipper will rip everything textured but combine the entire scene into one spot making the whole thing useless and it has hundreds of meshes combines.
Ripper DX will give a proper export of the scene in the correct places but without textures, sill skewed though thanks to the games camera.