On the other hand, making terrain in engines intended for indoor use such as Unreal and Quake III have far fewer geometry limitations, but bring with them the huge problem of visible polygons.  With no ability to detail-reduce distant terrain, outdoor levels in indoor engines must constantly take liberties with reality in order to keep the number of on-screen polygons down as much as possible.  As a counterpart to the “marbles in rubber” look of badly-done height mapped outdoors, outdoor FPS levels often have the “maze of canyons” look.

Finally, of course, and this is a problem that not even Trespasser solved very well, despite our best attempts, is the issue of object density.  Sometime, probably before too long, either raw polygon-pushing power or a breakthrough algorithm will permit the thousands of trees and bushes that will enable outdoor levels which look like something other than bare, rocky wastelands that just happen to be painted in vegetation-like colors.  For the time being, however, there is a tricky balancing act involved in object placement which many outdoor level designers seem to avoid altogether, going instead for the “one tree every quarter mile” approach.

Now, I’ve listed out the problems with making outdoor terrain, but just knowing what to avoid or work around is not the best way to approach the difficult task of making an outdoor level.  Much of the technique of making an outdoor level can only be gained through experience, a belief that nothing is impossible, and an unwillingness to accept the status quo of outdoor level design. However, I will try to condense some of my own experiences into a few paragraphs of positive advice.

The most important recommendation I can give is to learn a professional 3D modelling package such as 3D Studio MAX and learn how to use it with the engine of your choice.  Internally created editors, especially those created to make simplistic, indoor shooters, are becoming increasingly unfit for creating the complex, sprawling, organic geometry that today’s 3D cards and consoles are actually able to create.  Many companies are actually beginning to move all their geometry creation, world geometry in addition to object and character geometry, over to professional modelling packages, and using their game editor for gameplay editing only, such as placing objects and enemies and creating triggers for game logic.

Using a 3D modelling program requires a much stronger knowledge of the technology behind today’s games than the average level designer brought up in FPS editors may be used to.  MAX and programs like it allow users to screw around with geometry to its lowest level, right down to removing or adding in vertices and faces, and designers using it for game creation must be acutely aware of what constitutes good and bad geometry for their particular game. 

The engines I’ve worked with tend to go crazy if geometry has any gaps in it (a missing face – picture a cube with one side gone).  Poly-count has also been a critical issue and removing verts and faces and then rebuilding the mesh is a very easy way to get into trouble and accidentally create bad geometry.  I tend to start with the simplest shapes possible and slowly add detail by splitting edges and tessellating faces minimally.  As high poly-counts and curves become a part of more engines, however, it will probably become necessary to work with geometry primitives in your modelling package, and apply modifiers to them, rather than hand-editing their geometry at the lowest-level.