Hello! My name is Igor Rashkuev and I work at the local video game development studio as a concept artist. In this article I'll tell you a little bit about creation of my work Steam-powered Factory.
This work started as a concept art for a steampunk tower defense game, but eventually it grew into self-contained piece. I planned it to be traditional 2D art and even started doodling something in Photoshop, when suddenly I got lazy about constructing perspective and decided to create the sketch right away in 3D. Previously I thought that it's necessary to make a 2D sketch before any 3D activity, but it turned out that in some cases you can skip this step. I guess such cases are creating vehicles, different machinery, probably buildings, and other stuff that does not contain complex organic-like shapes. It frees you free having to construct perspective and lets you easily play around with shapes in space.
So I started blocking in basic shapes of this tank/steam-train/tractor/whatever-you-like-to-call-it - the same way you start something in 2D (Fig.01).
You see that initial idea was a little bit different. It was supposed to be transportation vehicle (that's why it doesn't have any weapons), so I wanted to attach a house-like thing to it, but it was spoiling the silhouette so I removed it later.
There was nothing particularly special about the modeling I did. I just started adding details; larger ones first, then smaller ones and so on. A basic rule (well, it's not a rule, more like a guideline - I believe there are no strict rules in art) is: group smaller objects around larger ones.
To make this process easier, firstly, I created repeating details like screws and gears. It's very important to copy such objects as instances - it would take an immense amount of time to edit them all after. It is also important that the original object has been given a unique name; it will make selection of all such details much easier. For example, imagine how much time I would have spent selecting all the screws individually when I assigned a material to them! And what if, after that, I wanted to change it again? Don't underestimate the importance of object management. Use layers, named selections and groups, and give objects proper names, and you will definitely appreciate this work when your scene starts to grow larger and larger.
To create hoses and the tank tracks I used the Spacing tool. It is a quick and easy instrument that duplicates objects along the path. It can be used unless you need to create dynamic structures - object copies won't move if you modify the path (Fig.02).