Sunday, October 17, 2010

A Design Process III: First Draft

Our new tank is now pretty well defined in the abstract, time to start on the actual design. At this stage it's helpful to have a good selection of reference images featuring actual tanks and vehicles from reality - if a vehicle ever engaged in actual warfare then you can be pretty sure that it was functional and should look the part. The sense of realism we desire can best be achieved by emulating real objects to a certain degree.

We also have a few parameters we need to work within if this new tank is to slot neatly into a tech tree with other units. The style of the thing is in many ways pre-defined - which can be equally helpful and restrictive. In this case it means we already have a library of detail objects from other Kautylian vehicles that can be easily added to our new tank to unify the look and imply standardised technologies. It also means that the lines of the new unit should be clean, straight, efficient and probably not stray too far from modern designs in order to best fit with the existing build tree. Modern designs are therefore an ideal starting point for inspiration.

One of many rejected drafts for this unit.
Early in the conceptual phase I mucked about with complex suspension rigs and other techy looking features, but they never really fit well with the economy and pragmatism of a post apocalyptic setting, and would totally outclass the Antiarchs. Most modern wheeled tanks in reality look more or less like this or this. Sure they look pretty badass, however perhaps a little too close to the existing Kautylian Medium ATV for our nefarious purposes.

Since we are creating a heavy tank and want it to look the part, something like this or this might be closer to the look we'd ultimately want - lean, mean, futuristic but definitely well within the realms of the plausible - using wheels instead of tracks will give ours a certain uniqueness. These also look solid enough to mount our big guns.

Next point on the brief is the semi-aquatic functionality - amphibious main battle tanks kinda integrate various features of boats and look like this (Google image search is the designers best friend...) -  in MAD they struggle on water so amphibious aspects can be minor, but should still be present.

The final consideration is logistics.

Most designers who dabble in this field should have a vague idea of the method used to create AAA FPS game assets. Here is not the place to delve deeply into that process, but it involves creation of a high resolution version of your game model that is used to "bake" ambient occlusion and normal maps onto the low resolution model. I'm not using that method for several reasons.

Firstly, unlike most AAA titles that feature vehicles, MAD has a much greater RTS slant and increased visibility - therefore vastly more vehicles may appear on screen at any one time than in Halo for instance. The downside to the texture baking is resource cost - each model needs it's own set of unique textures and this adds up very quickly when you consider the resolution each texture may also need to be.

Also because I am the sole designer on this project I have a lot on my plate, especially considering I also still need to pay rent. In order to punch out 2 or more full tech trees (plus all the maps, props, particles, textures, GUI icons etc.) I need to work with an eye to efficiency.

Therefore unit textures are shared as much as possible across each build tree. Parallax, specular and ambient occlusion maps are then generated from a heightmap, which I paint in manually based on the diffuse texture. It's less exact, but certainly functional and far less costly in terms of resources. Additionally, I tend to re-iterate designs as I get new ideas - shared textures allows me to do this much more efficiently and work on several units at once.

Currently the Kautylians use 2 textures, if possible I'd like to keep it that way. Many of the fine details like lugs and ammo crates etc will obviously lend themselves well to this kind of recycling - however to make life easier later when trying to shoehorn the UVs about, if I am creating any new geometry it should stick to shapes that will fit well to the shared diffuse textures. This bit can be a bit trial and error, but it is surprising how much variation you can get by just mixing it up.

This might fit the bill.
After a bit of mucking about in my app of choice, I arrived at the above as a first draft, decided to run with the boxy MBT look and replace treads with wheels. I kinda like it - the details are fast and loose, but it has that no-nonsense look I'm after. Currently it's armed with the Antiarch artillery weapon - because that is the bulkiest of the large cannons, the main turret hardpoints need to be designed around it. It maybe needs bulkier armour and more plating but overall it fits OK I think.

Although it's beyond the scope of this article to teach 3D modelling, the method used to create the tank above might be useful.

Next: Step by step.

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