Intro
Wade Muller, a Master's degree art student from the University of Sydney, Australia, shows us how to build ‘Corner of Cobblestone' from scratch...
Introduction
The idea for this project was to create natural textures and to experiment with V-Ray Sun. I will explain more about V-Ray Sun and the lighting I used later on in this article. The original reference image was taken of a building in my local area, Coogee, in Australia. The reason I chose it was because it had slightly dirty walls, but they were not to the point of being filthy. It was also interesting compositionally, and allowed me the ability to play with different lighting setups (Fig01).

Fig. 01
Modelling
For the modelling of the main building faces I used simple planes, then cut and extruded them to achieve the shape that I wanted. This also came in handy when I progressed to texturing because the faces were already separated. I split the building into three main parts; Left Main Face, Corner, and Right Small Face. All extra modelling was created using box modelling. There were certain areas where modelling was not used; instead I used either displacement, or a mixture of bump and opacity, textures to give form to such places as the balcony fences and the cobblestones (Fig02a - b).

Fig. 02

Fig. 02a

Fig. 02b
Texturing
Firstly, as I mentioned above, I used textures to create form, instead of modelling. The first area where I used this technique was the cobblestones, which are a V-Ray displacement. I just used an image and tweaked it in Photoshop so that the contrast was correct to displace the stones properly. The second area was the balconies, where I used a mixture of bump and opacity textures, instead of geometry, because they were placed far from the camera, and so in the light of scene poly efficiency I could get away with it. As you can see in the bump, all I did was take the opacity map and feather the edges. This allows the fence to appear rounded, similar to how it would have been forged in a metal workshop (Fig03 - 05).

Fig. 03

Fig. 04

Fig. 05
I then moved on to work on the glass in the front door, for which I wanted to achieve a foggy, bumped effect. So I simply applied a bump map to the normal glass that I made (Fig06).

Fig. 06