Chapter 3. Graphics for Mobile

Videogames strongly rely on graphics. The production of graphic assets for mobile games poses several challenges to game artists, mostly dependent on the necessity to both create nice-looking and appealing graphics while dealing with reduced screen dimensions and limited memory allocation. In this chapter we will describe how to create 2D and 3D assets for mobile games, what software packages and techniques can be used and what file formats support graphics for mobile games.

In this chapter, we will cover the following topics:

After gameplay quality, graphics are the most important factor in selling a game. Some have argued that good graphics are the most important factor in impulse buying, since most of the time a gameplay demo is not available. It sure looks good, it must be good.

This has been an ongoing discussion for decades, notably with the release of two games in 1990: Wing Commander by Chris Roberts and Balance of Power by Chris Crawford. Wing Commander had cutting edge graphics with light game play and storyline.

The following figure represents a screenshot from Wing Commander (source: Moby Games).

On the other hand, Balance of Power had brilliant and deep game play but amateurish graphics. At that year's Game Developers' conference, a debate (to put it mildly) ensued between the the two developers. Given limited resources, which is more important: content (game play) or context (graphics and sound) to the success of a game?

The following figure is a screenshot from Balance of Power (source: Moby Games):

At present, hardware capabilities have increased enough to allow both, with proper planning. The production of graphic assets for mobile games requires several gimmicks to make things work properly. Mobile devices have, in fact, relatively limited hardware capabilities: they lack the computational power of PCs and consoles. Since games give the most stress on the hardware capabilities they run on, it is very important to have assets that minimize the requirements while providing an optimal result.

Another important aspect that must be taken into consideration for mobile games is that, differently from home consoles and PCs, handheld devices rely on their battery. The more computationally expensive the app (or game), the shorter the battery life.

There's no point in having a beautiful game running on the device, if it runs for a few minutes and then the device shuts off. Again, optimization of a game's system requirements is a key factor, starting with graphics.

The hardware of today's devices varies very much from one model to the other, so that for a game to run smoothly on the highest number of devices, it must have the lowest possible computational requirements.

With so many different mobile phones available, each with its own hardware configuration, it can be a hard struggle to have your game running smoothly on the highest number of devices, which is mandatory for it to be profitable.

Fortunately, there are ways to overcome such obstacles. A good starting point is comparing the hardware of different mobile phones. The following link points to one such site:

http://www.mobiledia.com/phones/compare/compare.php

First, several techniques have been developed to allow the production of quality graphics that minimize the hardware requirements for games.

Second, technological development constantly pushes forward the hardware capabilities of mobile devices, and there are several models today that are equipped with a Graphic Processing Unit (GPU), a piece of hardware that specifically takes care of computing graphics. This way, the mobile phone's CPU is relieved from taking care of all the calculations required by a game, and as a result, games can run smooth and have excellent graphics at the same time.