After all the doors, small plants, windows – and every small object in the scene – had been modelled and textured, I began working on the walls. For the walls, the process began with a proxy, then textures.
Afterwards, I converted to polygons and added destruction by cutting into the geometry. This way I could maintain the UVs on each wall and create the destruction following the destruction of each texture (Fig.07 – 08).

Fig. 08

Fig. 09
Leaving the walls till last allowed me to bake the occlusion pass into the diffuse texture using the render to texture feature (since I already had every object in place). Doing the occlusion pass this way allows the objects to follow the scene lighting correctly. If you do the occlusion pass separately, instead of baking it to the textures, the shadows tend to be too dark and appear as though they don't "fit in” with the scene's lighting.
Finally, I began to create the ground. As you can see from my references, the ground that I had to do was fairly bumpy. I first tried using displacement, but render times became too long and for the animation there was a lot of flickering. So I worked on another technique (Fig.09).

Fig. 10
The first thing was to model the base mesh for the ground (1). Afterwards, I un-wrapped it and painted the diffuse, bump and the displacement textures. After applying the textures (2), I converted the mesh to poly so I didn't lose the unwrap information. I then used a subdivide modifier (3) on the mesh. That way, I could control how many polygons my mesh would have depending on how close my camera was to the mesh. Finally, I applied a displace modifier from 3ds Max (4) that let me see the displacement in the viewport. To finish, I modelled some plants and scattered them around.
Here you can see the final model (Fig.10).

Fig. 11
For the lighting I decided to try Vray sun and Vray camera. After a couple of tests I defined my final settings (Fig.11 – 12).

Fig. 12

Fig. 13
For rendering purposes, I used V-Ray with an Irradiance map and light cache (Fig.13). For the final image/animation I didn't do very much post-production work, just a little colour correction, as I had already done a lot of work on the textures (Fig.14).

Fig. 14

Fig. 14 - Final Image
If you're interested, you can check out the animation on my website:
http://www.omarfernandes.com.
I hope this Making Of is somehow useful for you! Thanks to all and best wishes.