Tuesday, 20 September 2011

Graphics and Development

Many free remakes of classic games, like OpenTTD/Transport Tycoon and CorsixTH/Theme Hospital, are programmed with the direct aim of reusing all the original game's graphics... By reusing the the graphics from the original game you are guaranteed to capture its look and feel and the immediate availability of graphics lets the coders get straight to work.

While this is an easy way to get straight into development it also restricts the coding of the open source remake. A commercial game and an open source game have very different requirements. A free remake of a game is supposed to be exactly that; free. Being tied to the original graphics means this isn't the case, users need a copy of the original game to get the required graphics files to play the remake. Open source games are also fueled by user generated content; if the coding of the game is tied to using the original graphics then this can push design choices in the coding away from flexibility and extensibility using custom graphics sets, etc., towards a rigid reimplimentation of the original game. Major changes, like designing a large GUI for use with touch screen devices, would simply be impossible if limited to only the graphics from the original game.

Because of these reasons FreeRCT will be coded in parallel to a large drawing project which will make the basic graphics for FreeRCT to use. The graphics will be designed in the same format as the original RollerCoaster Tycoon graphics (i.e. 8-bit paletted graphics, with the same palette as the original graphics) and will be designed to be essentially interchangeable (e.g. the terrain tiles will tesselate into a landscape in the same way the original graphics did). This means that, in the future the original RollerCoaster Tycoon graphics could be coded for use in FreeRCT, but up until that day the coding of FreeRCT is not encumbered by being forced to use the graphics from RollerCoaster Tycoon.

Don't worry though, we do aim to support the original graphics in the future to give people the option of an authentic RollerCoaster Tycoon experience!

The 24 sprites that make up the normal terrain with and without gridlines.

Designing all the graphics for FreeRCT from scratch is a challenge, especially when trying to capture the same look and feel as the original graphics. RollerCoaster Tycoon really reached the peak of what was possible with sprite (small 2D image) based graphics before the game industry moved towards 3D graphics. To get its high quality appearance RollerCoaster Tycoon used nearly 30,000 sprites. Fortunately most of the graphics can be generated from 3D renderings and scripted conversion to the correct palette and arrangement into sprite sheets... Getting this working is what my challenge is.

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