Though this discussion focuses on creating pre-fabs for an indoor fantasy environment, the same principles apply equally to science-fiction or modern interior settings. Don't let the genre throw you; feel free to make pre-fabs in any style that takes your fancy.

Click the image at the right to see a set of my sci-fi pre-fabs, complete with lightmapping and placeholder figures swiped from Polycount (by James Edwards aka Gwot, and Daniel Beswick aka Slightly Twisted).

This tutorial assumes you are familiar with the most

from Space Hulk BE by Michael Arrington

common gameSpace (or gameSpace Light) tools and have access to a photo-paint application such as JASC's Paint Shop Pro or Adobe's Photoshop.

As with any such tutorial you will need to make allowances for your own particular setup - particularly regarding 2D and 3D formats for your favorite game engine.

Part One: Laying the Foundation

A little planning goes a long way when designing games. In this tutorial we will create tileable 3D level components for a fantasy dungeon game. What's missing, of course, is any sort of information about the game in question. <sermon>While this is fine for a learning exercise please do not do this in the real world - you will save time and money if you plan ahead and start developing only after you have a good idea of the game you want to make, the content and code required, and other factors.</sermon>.

We still have to do a little planning, even without the details of our little generic fantasy game in hand. For one thing we need to think about the specifications for the pre-fabs we are going to build. It is important to establish details like size, texturing, tiling, and so on before you begin to model.
 

After a little thinking we might come up with:

• Level pre-fabs will be single, tileable 3D modules representing dungeon terrain - to be assembled in a custom level editor or in the game engine.
• Pre-fabs must fit within 10x10 unit square and will generally be 6 to 8 units high, though they can extend above and below these limits if desired.
• Pre-fab textures will be 512x512 and only one texture will be used on each pre-fab. Overlay textures with dirt, weathering, lightmapping, etc. can be used to create some variety in appearance.
• Each set of styles will have one or more pre-fabs that act as transitions between it and one or more other styles, e.g. dirty red brick -> mossy grey stone or rocky cavern -> random stone blocks.
• Additional props such as torches and chests may be added later in a level editor or game engine.

Not a bad simple specification for our purposes. We can use this to plan out a single 'style set' to build - think of this as a set of tiles that fit together interchangeably to allow you to create a section of a dungeon.

We will have 'transition' tiles that make the jump from one style to another seamlessly. The image at right shows the basic tiles we will need to build.

First, we need a tile with just one wall and one with a corner. This will allow us to build large rooms. We will also need a tile with walls on either side to serve as a hallway and a tile that lets us create a dead-end hallway (or a niche). With just these four tiles we can create a great many different dungeon maps.

There are a couple of missing elements though.
 

One is a plain floor tile, for the center of that large room we talked about. Also, our wall tiles won't include floor geometry, so we will use this floor tile under each wall tile. This will let us mix things up for more variety.

We will also create a roof tile, which will be used to cover areas outside of our walkable dungeon area.

Door are a must too; dungeon delvers just love to bash them down (some just listen at them...wimpy elves!) Finally, we will need to create a 'corner fill' tile. This tile will be laid down to fill gaps created when two tiles with walls meet at a corner.

That is a manageable set of tiles to start, though you can certainly add many more types of specialty tiles -

special rooms, traps, and other dungeon fare. At right is a sample of what we can do with our set of pre-fabs.

Well, maybe it's not the Tomb of Horrors or the City of the Spider Queen but the Underdark wasn't built in a day - and, with some work, this foundation will take us pretty far.

Part Two: Building The Walls

Now that we've done a little planning we can move to the fun part: actually making the models. Open gameSpace (or gameSpace Light) and let's get building!

First off, a template of sorts might be helpful. On the 'basic' Layer create your lighting layout - these screenshots use 'white' from the Light Library. If you want you can move the Infinite Lights out of your working area to avoid visual confusion. Next, create a Cube primitive with no divisions and use the Object Info box to change its Size to 10, 10, 6 in X, Y, and Z, respectively. Then, change its Location to 0, 0, 3 in X, Y, and Z. When you are done, Add New Layer and Lock 'basic'.

We will build our first pre-fab on the layer just created. Let's start with the single wall pre-fab mentioned in our list above - should be easy, right? Well it is! Just create another cube with no divisions. Again using the Object Info box, change the Size to 1, 10, 6 and change the Location to 4.5, 0, 3. That places it flush against one wall of the cube. You could stop now, if you like boring dungeons - but let's spice it up a bit!

Before we do any more modeling, let's get rid of the parts of the wall we won't ever see. For our purposes we only really need the top and inside faces of the cube - everything else can go away. Right-click on the cube to enter Point Edit mode and select the Delete Faces icon. Then, click each of the faces to be removed to delete them. You should end up with something like the image below - note that the reference cube layer is Hidden in this screenshot.

Great! Now, let's add some detail. You can stay in Point Edit mode because we're going to add just a little geometry to make our wall slightly more exciting. Dungeon walls are notorious for niches - where else are the little nasties that live there going to put their sacred urns and whatnot? Let's make one. Clicking on the Polygon Draw tool will let us create a new polygon directly on the wall face. Do that and create a nice little niche. Things don't always square up well so either move the vertices to the right spots or click on them and change their location in the Object Info box.

Using Add Edges and the other Point Edit mode tools you can keep adding detail to make your pre-fabs as complex as you want. Of course poly count may become an issue depending on how many of these you are going to have on screen at once. If the user has control over the camera in your game you have to assume that he will find a way to use it to your disadvantage. You should be safe if you stick to a few hundred polygons for most applications - even with minimal visibility checks.

For the early stages of this series we will stick with simpler models, we can always make more complicated models after we have the basics down. In the next installment of gameSpace Fantasy Pre-Fabs: Getting Started With Pre-Fabs we apply UV mapping to our wall and create a texture for it. Beyond that we will look at creating some decorations to sprinkle around our dungeon and how to get these things into a real game engine. Stay tuned - there's more to come!

gameSpace Fantasy Pre-Fabs Tutorial: