Hello, my name is Daniel Vijoi and I have been working in the gaming industry for 7 years. My current job is Lead Texture Artist at AMC Studio, a Romanian game development company based in Bucharest. During this time I have worked on many projects, like Test Drive Unlimited (Atari), Mercenaries 2, Saboteur (Pandemic Studios/EA), Pure (Blackrock Studios/DISNEY), Rise of Nations & Rise of Legends (Big Huge Games/THQ), and other exciting titles yet to be announced.
I decided to write this tutorial as I noticed a certain lack of interest for game-related environmental texturing in the 3D community. This tutorial is targeted at medium level users and will present the process of texturing a photorealistic building that has already been modelled. I will focus on the texturing process in particular, even though the modelling and UVs are also important for the final look of the building.
For this tutorial, I used the 3DTotal Texture DVDs, a large library of diverse textures that we here at AMC Studio use regularly. At the end you will find a list of all the specific 3D Total Textures I have used for each texture that I have created. Some of the images included in this tutorial also mention which textures were used.
Usually, it is preferable that one artist does the entire process of modelling and texturing, as usually these processes are interlinked, so optimising the geometry will make changes to the texturing, and vice-versa. This is why I will also mention some of the means by which the geometry and UV have to be optimised to keep the textures needed to a minimum, whilst also adding extra details and personality to the asset.
The majority of game assets start their life as a concept art and some reference images that will help to better define the character of the building. For this tutorial I used the following concept art and reference photos (Fig.01 - 02). The subject of the concept is a desert building, inspired by the settlements on Tatooine and typical real-life Tunisian buildings. I also included some extra sci-fi details to make it more interesting. The desert environment will influence the chromatic variation of the textures as well as their detail, as far as weather influence on materials goes. Being a multi-purposed building, details vary; there is a generator in the tower and the back side of the building can be used as a market stall to sell different things.
With the help of the concept and reference pictures, I modelled the low polygon geometry. The model has 2500 polygons, well under the 2700 polygon budget set initially. This will allow me to add further cuts in the geometry to optimise texture usage later on in the process. Here's a screenshot of the building geometry from two different angles (Fig.03).
Here you can see the same geometry with the UVs unwrapped (Fig.04). The checker texture was added to make sure all the UV shells are proportional and that there are no areas with deformed UVs.
Before texturing, a quick drawn texture layout would be in order (Fig.05). This can be done either in Photoshop or on paper. This makes the texturing a lot easier if the layout part is sorted out beforehand. Because this process is rather quick, I usually sketch a couple of versions before I decide which the best one to use is. First of all, the entire geometry has to be measured properly so that the UV layout is as compact as possible, with as little unused space as possible. Large areas on the geometry will take up more space on the UVs than small areas. In this case, I chose the keep the texture resolution at 128 pixels per metre. This will allow me to keep all the UVs in proportion with each other and also figure out how much space every detail on the building will take on the texture. Having all the parts at the same resolution will ensure that no area of the building will appear to be blurrier than another.