This phase of the tutorial was the most involved part of the process and used two principal techniques: unwrapped geometry and Composite maps.
It is often useful to know the rough size of your final render in order to create templates that are a suitable size. For example; if the foreground wall was to be unwrapped, the width of the template should approximate the width of the render.
Having said that, it is worth creating larger textures initially as they can always be scaled down later, but if the textures are too small then it will cause a problem. If there is any chance that your work may be published then it is safer to create bigger templates which will then account for any printing issues.
When texturing I usually start with the most conspicuous areas first and then work my way down to the sections that are least noticeable. That is not to say that minor sections and details are not as important, it's just that these will have less of an immediate impact.
I began with the wall as this occupied a large proportion of the render. In order to control the details and grime fully I decided to unwrap this section of geometry.
Fig.04 shows the template in the centre of the image with some of the key textures surrounding it. I tiled the Base Layer to fill in the wall and then pasted in the remaining ones, which were color corrected and adjusted to blend in with the others.
As I wanted a distressed and aged look I chose three textures from V19 - Total Textures "Destroyed & Damaged"
collection, which proved ideal.
The next phase was to apply some dirt and grime, this time courtesy of V05:R2 - Total Textures "Dirt & Graffiti"
. I sifted through the library of images and selected a handful that was most appropriate (Fig.05).
With each of these four textures I inverted them so that black became white and vice versa. Then I set the blending mode to Multiply. I then reduced the Opacity to between 40 - 60% and adjusted the Color Balance to add more red and yellow.
The bottom right texture was set at 100% Opacity where the dirt and grime has built up the most.
Another section of the scene that I decided to unwrap was the metal panels. The reason for this was that these are a distinct feature in the scene and I wanted to be able to create variety and detail across each one individually.
I sampled textures from a few of the Total Textures collections, which incorporated metals from V2 and V3 as well as some of the worn doors from V17 - "Urban Extras Textures"
. I overlaid one or two few dirt maps from V5 onto some of the panels and made sure that each was color corrected so that they looked consistent (Fig.06). You can see how they appear in the render on the right of the image.
In the case of the buildings I chose to use a Composite map, as sections of the walls were covered by the panels and unwrapping seemed unnecessary. The great thing about using this type of map is that each texture can be positioned independently through the Coordinates section and color corrected within the editor.
Fig.07 shows the map used for the central building on the lower level. You can see that three of the layers are controlled by a mask with the upper two using a blending mode other than Normal.