Final Process
After showing Nick the render from previous week, it was pointed out to me that the lighting was incorrect. I adjusted the lighting (see below), to have more defined shadows of the machine appearing on the backwall and the left side wall. Due to the lack of time, I only rendered out the new shadow pass, such that the the new shadows would get combined with the beauty pass of previously lit up scene. Here is the result.
First render Second render
I also rendered out a frame of the new beauty pass, to see how it would have looked in the scene with the new lighting:

When the rendered files were imported inside Nuke, I didn’t break them down into different passes and combined back together, as the final output would look different to the beauty pass. The only exception was for the shadow layer, as the beauty and shadow render layers were exported separately, thus giving more control over the 3D asset.
I did use the ID passes, to affect the colour of the wheel, make it slightly deeper and darker tone. Same was applied to the golden features of the machine on top of it. An attention had to be payed specifically for couple of objects that appear to be in front of the machine. For those, I created a roto shape, which I then planar tracked and combined together using the merge node with operation ‘over’. Inside the lamp, however, is supposed to be some glass object, maybe see-through space, so a roto for it had to be cut out from the previously combined objects. All these alternations then were used as an alpha channel for the mask, to put original footage over the merged.
Lamp roto Bricks roto Rock roto Inside of lamp roto Alpha channel

Self Reflection
Looking back at the entire process I have learnt a lot about the integration of modelling and compositing in such an extensive project. I learned more about lighting, animation, rendering in itself, how to manipulate various passes and adjust potential mistakes later in Nuke. There were a few things which I was proud of, but not without a couple of mistakes and few realizations of what and how it could be done better.
Firstly, I could have implemented various machine parts, without attempting to copy entirely a whole machine from the original source. If I had done more of research and understanding of where it would have been placed, it would have been more clear to me of whether having a lot of small details was necessary. After all, the machine model itself has a couple of detailed bits which are barely seen or not at all. Secondly, I would have wanted to implement more of rigging, rather than just animating parts. Having encountered problem of understanding how to rig specific parts, I ended up using constraints, joints and IK only on the curve-shaped rod attached to the rotating wheel.
After a couple of weeks, modelling of non-organic objects became easier and easier, so I really enjoyed modelling the smaller bits or unusually shaped parts. When unwrapping the UVs it took me a couple of tries to understand how that would be working. As most of the parts weren’t seen much or actively animated, I attended the parts that needed most attention. Texturing was fairly easy and straightforward, especially with an outside look: pointing out what is unrealistic and how to make it look more worn down. Using Mudbox to make my own textures for the wheel and screws gave me some room for creativity and unique attention to those parts.
At the final stages of lighting the scene and trying various renders, we found that the HDRI was from the first room and thus created incorrect lighting for the scene inside the second room. Via trial and error, I placed lighting around the scene and experimented with the settings of exposure and intensity, to match the lighting reference of the rocks on the ground. I rendered out the variations of the scene and placed into Nuke script, to see how it would look in the end. The biggest mistake that I made in my final render was the use of HDRI to cast shadows and not blocking out enough light from it. The light coming from the left side of the room would create the highlights and specular details on the left side of the machine (e.g. edge of the wheel), which don’t match the shadows that are stretched out towards that direction. As I adjusted the lights after constructive criticism from Nick, I rendered out a single frame to see how the lighting would work for the whole scene, whilst rendering out the entire sequence just for the shadows. Overall, the shadows do look better, but they contrast slightly with the specular details which don’t belong there.
All things considered, I would re-organize my own time and shift my focus on breaking project down into a more detailed plan, such that I could see overall picture and leave reasonable time for render tests. Despite all the mistakes and issues along the way, I am pleased and satisfied with the result. This project gave me some ideas of what I want to do further in the software and what I want to learn about more.