Merricksdad's Gmax Tutorials: Create a basic tileset

In this tutorial, I'll walk you through the methods to create a very basic tileset.

This series features X videos. Each video is both linked and embedded in this script. If you would like to view the videos as a playlist, visit:

https://www.youtube.com/playlist?list=PL5ocXJqMTYcOxpvavEpUSgQ4fN_7MhRIp

What Tools You Need

GMAX

NWMax

A Paintshop-style art program (I am using PSP 7.02), unless you already have textures picked out

A text editor (I am using Notepad++)

A SET file editor (I'll be using Set File Editor Beta 0.85)

You may want NWNExplorer

Part 1: Planning

The first thing you want to do is determine a few attributes of your tileset. You really want to do that before you start making models for it.

1. Terrain types, like flat ground, mountains, or rivers
2. Reusable features like little rock walls, roads, or small streams
3. Unique features like buildings, cave entrances or giant trees: stuff you wouldn't use a placeable for

One main feature of the NWN tileset structure is that tiles are placed edge to edge, with only a few exceptions:

1. Tiles can be grouped together as a unit and placed as a group in the toolset.
2. Tiles can be raised or lowered by a number of meters which is dictated by a line in the SET file (but only by +1/-1 increments of that number of meters [at least in the toolset])

This feature allows you to create reusable tiles, as opposed to just painting the entirety of the map with various types of terrain. But, because of that feature, NWN intends you to use maps that look like this...

...but not so much like this...

Can you make areas like World of Warcraft? Sure. Is it intuitive? No, but it can be made to be so. But first, let me show you what you can do with a tile-based system.

Fate, Torchlight, and Torchlight 2, all tile-based.

Vanhelsing and many other similar games, ultimately tile-based, though you can't very well tell.

All 3 Diablo titles, tile-based, and they aren't even trying to hide it.

Even games that don't look tile-based, are usually tile-based. Kingsroad is actually chopped into large square sections and loaded as needed.

In fact, there are a ton of games out there that are actually tile-based. Even games like Dungeons & Dragons Online.

So what can you do with tiles? It seems obvious: Everything. So then what are the limitations? There are a few:

Elevation and the Height Transition Setting

NWN works on an engine that is really only 2d. Unlike many other games today, you cannot walk under a portion that you can also walk over. Ie. there is only one level of walkable game. You can't hide up above another player on a ledge and jump down on them as they come from a hallway under you. You can't walk over a stone arch bridge while another unit moves under the bridge (without some interesting scripting). The game simply isn't made for it.

As I mentioned before, the tileset only lets you raise or lower tiles by +1/-1 of a pre-set height transition in relation to it's adjacent tiles. This means you can't have elevational changes that vary by 2 meters here, and then 3 meters there, and then 5 meters way over there. So no areas with big cliffs and smooth hills, unless you do more work. Can  it be done? You probably know it already has. Is it easy? Well, like with everything else about NWN, it has some fundamental limitations. With every type of terrain change, you need to make an increasingly exponential number of mixing-tile types. You can mix water with flat ground, or water with a cliff, or water with flat ground AND a cliff. You can basically mix any four things at once (one per corner of a tile).

Elevation changes can either be a terrain type, or it can be a height transition. Depending on your area's needs, you might need a single elevation change, and you might use it often to create a slope, so you'd use the height transition. But you might also want multiple heights in your area, all of different levels, and then you want to also transition directly from flat ground to a really high cliff, so you'd make all your height transitions terrain types.

Can you mix the two? Yes. Does it have some issues? Let's just keep with the theme: yes it has issues. At some point, your height transition and your terrain-type elevation changes will run into an inescapable issue, which is that they become incompatible at a certain height combination (two height transitions). I spent an entire year trying to work around this and found that the game has no issue here, it is the toolset. I won't go into that further here, but if you go so far as to attempt what I did, and you want the scoop, just ask.

So what is the best height transition value? Well, many of the tilesets in NWN use 2 meters, or approximately the height of a human-sized bounding box. I've also used both 1 and 4. For any other height transitions, you might as well just use terrain types to make your elevation changes.

Terrain and Crossers

Your area is made up of one or more terrain types, patched together like a quilt. Crossers are like a neat pattern you can add between the squares. Terrain is what is at the corners of your tile, and crossers are what is on your edges. Crossers can be a type of terrain, like a stream, or they can be an obstacle, like a wall. Crossers can also match one of your terrains, but not too many people make use of that.

Common terrain in NWN includes:

1. Basic floor, or the primary terrain style of the area, such as trees in a forest
2. Secondary or more decorative floor type
3. Water or Lava
4. Pits and Chasms
5. Mountains and unreachable areas, commonly used as edges

Common crossers in NWN include:

1. Walls/anything you can attach a door to
2. Corridors/thin hallways
3. Streams
4. Roads/paths

When crossers pass between two terrain types, they often make some kind of separation. But in some cases, they change the functionality of the terrain they cross through. For instance, a stream crosser which passes between two edge terrain tiles (such as in the vanilla rural set) makes something you can use as a door. The same with a road crosser and edges.

Likewise, when crossers meet in the middle of a tile, they may become something else. For instance, when a stream crosser meets with a blank crosser in the middle of a forest tile, it can make a spring (the water has to come from somewhere). Another example: when a stream and a road crosser meet, they make a little bridge.

For every one of these possibilities, you need to make at least one tile to suit the occasion. If you don't, then the toolset won't allow the crossers to meet. The same is true of terrain. If you want your mountain edge tile to be able to meet a forest edge tile, then you have to have a tile for that, or the toolset won't allow you to attempt it. Height transitions are handled the exact same way

OMG! How much work is this going to be?

Maybe not as much as you think. Maybe more. Let me show you the 6 basic tile types: Full, Half, Quarter, Three-Quarter, Diagonal, and Inverse Diagonal.

The Full Tile

To create any tileset, you need at least one terrain. Let's call that TERRAIN A. You need a single tile where all four corners are represented by that terrain. There you go, you are done. The most basic tileset.

If you want a second terrain type, TERRAIN B, then you need a second full tile with all four corners representing that terrain. But, to actually use TERRAIN B in a map specified as being TERRAIN A by default, then you need a minimum of 3 mixing tiles.

The Half, Quarter, and Three-Quarter Tiles

I think the image above is fairly self explanatory, but just to be sure: If you have a tile with mostly or partially any two terrains, then you need these three tiles, or you can't use any of them. With these three, you cover the possibility of a diagonal touch (corner to corner) or an edge-on touch (the Half tile). The only reason you would not need all three is if you were using TERRAIN B as an edge tile only, in which case you would still need the three-quarter tile, and the half tile, but not the quarter tile. Again, if you omit any of these three (or two in the case of edge-only use) then you can't use TERRAIN B in any map with TERRAIN A because the toolset map editor does not allow what it cannot complete.

Diagonal and Inverse Tiles

In the event that you want to have two of the same tile intersect with two of another tile, in the pattern of an X, then you need at least one diagonally terrained tile. This means that in the upper left and bottom right corners of the tile, you need TERRAIN A, and in the opposite corners you need TERRAIN B. There are many ways of doing this, but I prefer to make two tiles.

In the first tile, TERRAIN A is dominant in that it is assumed you can walk in the terrain A top corner to the terrain B bottom corner, but it may be an obstacle to transition to terrain B in the other corners. Think of TERRAIN B as a chasm or something with the TERRAIN A corners meeting as a bridge in the middle. In the second tile, I do the opposite: the chasm meets in the middle and leaves two ledges at the opposite corners. I call this the Inverse Diagonal Tile.

Do you need both? No, but if you don't then you have less variety. I actually like to make no less than 3 of any terrain combination tile. In the case of diagonals, I may make two of each instead of having 6 total diagonal mixes.

Mixing Two or Three Terrains

Now, let's say you have TERRAIN C and TERRAIN D, which might be like a mountain and water. To mix three terrains, you need first a set of 6 more tiles, shown in the diagram above, to mix TERRAIN C and TERRAIN A, and than ANOTHER set of 6 to mix TERRAIN C with TERRAIN B, and THEN, you also need another set of nine more tiles shown below:

Yeah! That diagram shows that you need to have a pair of mixed-halves for any of the three terrains, and a mixed-diagonal for each terrain. Without these, you can't mix three types. So, what is that now? 1 + 6 + 6 + 6 + 9 = 28 tiles just to mix 3 terrains. Bla!

But NWN lets you mix up to 4 terrain types. To do that, you need another set of 6 to mix D with A, 6 more to mix D with B, 6 more to mix D with C, a set of 9 to mix ABD, another set of 9 to mix ACD, another set of 9 to mix BCD, and then a panel of combinations as shown below:

Mother of !...

OK, this is probably getting scary for you right now. And this is just 4 terrain types. You can't get much more basic of a tileset than that. So what do we have now? 28 + 6 + 6 + 6 + 9 + 9 + 9 + 6 = 79 tiles! And that is just counting one variation of each combination. If you didn't have respect for anybody making tilesets up until now, then you probably either think they are insane, or you just gained that respect needed to jump into it yourself. Also keep in mind, you can still make special groups and individual tiles that are much like placeables. And we haven't even gotten to tiles with crossers yet.

So as not to scare anybody off that has made it this far, let's just skip the diagrams for crosser creation and move on to another part.

Texture Selection

You are going to want to know what kind of textures you want to use on your models. For many, you may want the textures ahead of time. You can do your tiles in a few different ways.

1. You can chop sections of the tile to bits and texturize each bit. You'll have seams at the textures, but you can cover those up with some panels of grass, or maybe a brick border or something. Anything you can do to cover the seams because the materials used on each section will not soften at their edges. There will be an obvious lightning difference. You'll have individual files for each type of textured section, just like vanilla NWN does.
2. You can create complex textures and wrap your multi-terrain tile model in a single texture (minus the placeable-looking stuff). This lets you make much more smooth terrain changes. You may have one or more textures for the entire tile, but each tile will likely have a specific and complex texture.
3. You might make a texture atlas, a single texture containing all the paint work you need for the entire tile, and then use that to paint "elements" at a time. Your atlas might also include the entire texture requirements for the whole tileset, minus bits you need to animate or modify with TXI files.

The texture on the left is one I made back in 2010 which can be used top to bottom or bottom to top, and can be made to wrap a variety of the tiles I made for my huge tileset. It is an example of making more complex textures to wrap the main body of a tile, instead of cutting it into sections and texturizing each section individually. If you chose this way, you may need about 16-32 of these kind of textures to wrap an entire transition between 4 types of terrain, as opposed to having one texture for grass, one texture for the rock, and one texture for the transition area. It gave a much more smooth appearance than the alternative, but it could still be improved upon with a texture atlas.

The texture on the right was made around the same time when I attempted to make a tileset that looked more like the stuff in Baldur's Gate. I painted a boat load of detail onto the complex texture, which served as a transition from my stream crosser to a water terrain, which was a larger river rather than a lake. Again this texture was very specific, and so was ony used on two tiles total. It would have taken 4-8 individual textures to pull off what it was able to do, and the model would have needed to be split into a lot of sections with seams. Like the one on the left, this one would have been even better as a texture atlas.

    

A texture atlas is nothing more than a single texture file with a bunch of resources on it. Here's one I used for weapons quite some time ago.

To make a texture atlas work for you, it would need to contain enough of certain textures that you could use that texture on mulple shapes. For instance, when you wrap certain shapes in GMAX, the tverts go outside of the bounds of the square texture, and it is assumed that the texture repeats. In the case of a texture atlas, you need anything wrapped to fit within the bit of texture you supplied, or it will pick up the neighboring texture. That would be very messy. It also means you may need to locally repeat a certain texture in your atlas 2 or 4 times in a rectangle to increase the usable area of that texture. It seems wasteful, but the benefits are also very useful.

Some suggestions for textures:

1. Your textures can be greatly modified by the environmental scheme you choose in the toolset. I suggest using textures that fall in a mid-saturation range. Only brighten those things you want to pop out. Let your lighting elements and shadows do the rest.
2. Your textures will be softened by the engine. I suggest picking grainy textures so you have more detail after the smoothing process.  See Dungeon Siege 1
3. If you use hand-painted very detailed textures, then make sure they are larger so they don't smudge down and look like plastic after environmental effects are applied. See Torchlight 2
4. Except on objects that will always be small, be sure to make everything else have a texture at least half the size of the tile. A tile is 1000 units wide, so a texture of 512x512 is sufficient. The ground and larger objects in your tiles will not be the primary catchy points which draw your players to the tile.
5. If you intend to use only NWN vanilla placeables, then make sure to make your custom textures fit with the vanilla textures. You can also draw upon the texture files associated with pre-existing tiles.
6. If you intend to make a tileset that is dark like Diablo games, then you might as well reduce the size of your texure and create crisper edges within that texure. Diablo 3's lighting style basically gives the player the appearance of actual water and trees. They don't actually define anything that is dark.
7. Less detailed textures are great for games which are dark, but realize your shadow engine is going to be doing a lot of texturing for you, and so you might need more complex shadow-casting objects. Brightly lit games will require a lot less polygons, but will require better contrasting textures.

That is really enough planning for now. I'm only going to do a rolling hills basic set, so there isn't much more that that to do.

Part 2: Building Basic Tile Meshes (https://www.youtube.com/watch?v=rM7324QJY1s)

I'd like to make a tileset which I could use for some open outdoor fun, maybe ride a few horses around. Lets take a little Scottish Isle of Skye, mix with some Canturbury New Zealand, a pinch of Appalachia, a tad of South Dakota and a dash of Wyoming. That should do!

I've imported a few individual textures into GMAX already. I tend to use a palette system where I make these little spheres and paint them with the textures I will likely use. It lets me get an idea of what the textures will look like when rounded. I can then just do GMAX file merges to move the palette from one file to the next.

Here are some images from when I did a similar tilset back in 2010 (before it was fleshed out, mind the lack of extrusions).

         

         

So let's recreate that in GMAX and go forward from there.

This first video has been redone so many times, and reduced in size so many times, that I may have to partially rewrite the format of this tutorial to get it right. After all that, you can at least get a good look at the 3d views of the 6 tile types I was talking about in part one.

Sharing Seams

I'd also like to go over those adjacent tile plane tricks I was talking about in the video. In-game, as much as some people would like to think that the engine does some tile-to-tile smoothing work, it really doesn't. If you don't make your tiles in a certain way, you will most definitely see seams between your tiles.

I don't mean texture repetition seams, I mean smoothing group boundaries. From tile to tile, each model has a separate set of smoothing groups. Those groups do not match up to the groups created in adjacent tiles, so if you set ALL faces in one tile to smoothing group 1, and ALL faces in an adjacent tile also to group 1, you still have two groups.

One thing you can do is reduce the angular difference from one tile to another. In the video I stressed the importance of making extra faces around your tile edges that exactly match the planar facing of adjacent tiles. To do that you have a few options, but the easiest, and most likely to be accurate, is simply to match up the x or y coordinates with the adjacent tile and extend those coordinates into your tile at least 1/32nd of the tile size. There is no reason to really get to measuring that value. I am just saying 32nd because you really need next to zero pixels of that extra plane.

So what that does is makes the appearance that one tile continues into the next. With zero difference in the planar facing of a polygon, the visual seam will be reduced to as little as possible. It is still possibly you can position the camera just right, or even introduce a light source, which magnifies that seam. But doing this technique makes it much harder.

Once you get the hang of that seam sharing, the per-tile smoothing groups will take the rest and work their magic. Anything you can't seem to get rid of you can always cover up with decals or other patches later.

Part 3: Defining Crossers, Terrain and Height Transitions

In video one, you can see I constructed an obvious height transition. But you don't have to use the height transition that way. You can use it as a terrain type, as I was mentioning in the video. The only difference with a height transition is that the toolset lets you repeat it from tile to tile, going up, up, up from the base level. With a terrain type, you can only use it once and never go higher, without of course making more height transition terrain types.

But how do you decide how to define them? Well, it totally depends on how you want your tileset to be when finished. Lets say you have a very Scottish Isles tileset. You will have large cliffs, and short cliffs. You'll have rolling hills, and some flat places. In that situation, you can either use repeated short cliffs to represent a larger one, and then use larger cliffs as a terrain type. You'll never be able to mix those two except at 1x multiplier of the hight transition. What I mean is, you can never use your very high terrain type adjacent to a high place built up from multiple height transitions. The toolset just won't understand that.

Still not sure what you want to do? Well, remember NWN is made up of both role playing areas and combat areas. For combat, you have specific needs. For puzzles and conversation bits, you may have totally different needs. Let's focus on combat. Many games have large open areas, let's call them community combat areas. Many players may be in the area fighting random creatures. This area should probably be generally open, or should have large open areas with definite dividers. So in this situation, you might want a tileset which has no height transition, but uses one or two height-change terrains for dividers. The player might be able to reach the higher levels, but it is not a requirement for the area.

So how about other area types. Maybe you have discovery type areas. These might have very few monsters, but might have a puzzle. The entire area might be a puzzle that you have to keep traversing. In that situation, you want the area to be visually interesting, because the player is going to see it a lot. I'd suggest a height transition, used multiple times, and then mix with a few other terrain types.

Let's look at some common terrain types:

Grass (or base terrain)

Most outdoor tilesets make use of a base terrain. The area is set up to automatically paint with that terrain type. Vanilla rural areas are simply 0-height transition grassland. Grass is most commonly used also as the height transition terrain type. It is probably best to make your base terrain, whatever that happens to be, the same one you use as a height transition.

Rock (something impassible)

Outdoor and cave-style terrains often have a border terrain type. In many of my tilesets, I simply call it impassible rock. I don't let players walk on it, and I generally use it to wrap my areas so players can't see the engine-dimmed edges ( I hate how the engine does that ). I also include impassible rock as a crosser. Whenever I want to elongate the unusable area at a height transition, I insert some impassible rock. Let me show you.

...a very basic height transition...

...same height transition smushed out with a crosser...

Trees

Vegetation, such as trees, can be used in a lot of ways. First, trees were used in the vanilla rural tileset as an edge type. It could also be used to create separations within the area. There were no pathways which could pass through the forest sections. Second, in the forest tileset, (tall) trees were the base terrain, and so you could walk through the areas dominated by trees.

But you can do more with trees. When I was playing Dungeon Seige one summer, I took a lot of interest in how they used trees as both a border terrain, as a mid-tile terrain, and as something that looked more like a crosser. So I started experimenting with trees as a crosser and came up with shrub colonies and fence rows. I made them so you can walk through them, at least most of them, without issues. Both players and monsters could use them as cover, so I also used them to hide spawn points, especially for creatures with custom appear/disappear animations. Take for instance our scottish isles terrain: a common terrain crosser might be a property/plot separation, such as a fence, a rock wall, or even just a tight line of trees.

Water

In standard rural tilesets, water was immediately so deep you were never allowed to walk in the water. But water was also used as a stream crosser that you could easily walk through. Both were fairly unrealistic in their depths, but I could imagine the world being created by dwarves with digging machines if I stressed my brain hard enough.

When I took on water in 2008, I differentiated water based on its adjacent terrains. You may need instantly deep water, like you might find in a mountain setting, where water collects in natural or man-made reservoirs. But you might also want something more representative of a freshwater lake, in which case, you definitely want a gradual transition. On a trip to Pictured Rocks here in Michigan, I studied and took time to sketch the shorline. I wanted to know how the sand, rocks, berms and the shoreline acted on each other. I found in many sites that you could have a sharp drop from a cliff directly to the water, which might be deep. You could also have a shallow area that stayed shallow for quite some time, and in some cases, you might have a wide beach area. Or in some places, the beach might lead eventually into a berm, or a cut in the area's normal height level.

Decide what you need to do with water, and whether or not the player and monsters can walk in it.

Lava and Chasms

Like water, these terrain types might be an obvious divider to the area. Unlike water, there really isn't much possibility that you would want your players to travel into them. Instead, you might want special tiles that cross them, such as bridges. Again, think about if you want a larger portion of your area to be filled with these types of terrain, or if you want to use them as crossers. As a crosser, lava could flow like a stream, or a chasm could be a crack in the ground. As terrain, lava could be a lake, or a chasm could be as deep as the Grand Canyon (or whatever you can see with the fog level set in your area).

So Let's Talk Crossers

To be extremely general about it, crossers are the same as corner terrain, except that they are in the middle of each side. That means, just as with corners, you have four edges, or crossers, to a tile. If we divide the tile icon further, this is what you'd see.

Basically, the number of alternative tiles for any combination of 4 corners just multiplied by a power of two. You can either ignore that little square in the center, or like I do, you can count it as the center section when you name your tiles.

So how would you use this expanded grid? Instead of 4 parts per tile, we now have 8 or 9. Well, let's take a look at streams/rivers as crossers. In vanilla rural areas, streams travel down the center of tiles. To make a complete set of streams, you need these combinations...

...or to make rivers cross or join, you might want these additional tiles...

That seems simple enough. And the same set would be required for roads, paths, river variants, and on and on. Five specific tiles and as many variants as you like. But let's say you want a bridge crossing your stream. Would your bridge be a crosser? That depends. For instance, if you have a randomly placed bridge over your stream, but no real path leading up to the stream, then your bridge can simply be represented as a variety of the stream tile. However, if you have a road leading up to your stream, and you want the bridge to be represented by the road, be able to attach to it, then you'd want a second set of crossers for roads in which meeting in the middle creates the bridge over the river, like this...

...you would still need the set of 3-5 tiles mentioned above for roads, and the set for streams, and then you would need this one for where they meet. I've overlaid my crosser box icon over some old river tiles I made, see below:

Note that in my river crossers, instead of running the river down the middle of the tile, I ran it along an edge. There is nothing that keeps you from doing this, as long as you have enough tiles made that they line up. See in the picture, I have rivers that run on the right hand side, and rivers that run on the left hand side. But always, when my river goes around a bend, it is on the outside (really just for ease of creation). You can also see I have snaking tiles where the crosser changes handedness. I also have a non-crosser bridge which happens to cross at one of those snaking tiles. Just remember that if your texture moves or otherwise animates in a direction way, that you need two varieties of each tile. One going upstream, and one going downstream.

And if you want a stream to meet at a water terrain, then you might like these diagrams...

... where the top two on the left are where your river comes into the corner of a lake, or otherwise leaves a lake, and your top right being where the river meets a lake in a more perpendicular manner. The bottom icon could be where maybe a river meets a low spot but continues on its way after exchanging some water with a pond. Can you do more river-water combinations? Sure, but you start to run out of useful tile space when you have a river parallel to the edge of a lake. You need to draw a line for your area, and that is: Are you running a national geographic special for your scenery, or are you building an arena for players to kick the shit out of monsters and bad guys? Find your line.

But get creative with your rivers and crossers. Mix your terrains and crossers and make spectacular waterfalls, which maybe hide a cavern. Make a lava waterfall that pours directly into the ocean. Make springs well out of the side of a rock face. It is completely up to you. In any case, this simple combination of crossers is what you would use for roads, chasms, lava streams, small rivers, paths, walls, and so on.

Ok, but let's say your crossers are for use with terrain changes. For instance, if you want to smooth off the hills we made in the first tileset video, you would need a crosser called "smooth" (or similar). You would then place that crosser at your terrain boundaries to make the hill much less angular. Let me show you...

...the tiles above are your basic crosser plans. When you think of crossers that make terrain transitions, you have to think of handedness. You will need a crosser which handles the right side of any combination, the left side, and then both at once. If you follow the columns down, you can see that the first box handles smoothing on one side of a quart tile, and then the next handles the other side, and then finally the bottom one handles them both smoothed.

Not too hard right? But did you notice I left out the diagonal tile type? Please don't hate me, I am only the messenger. Here are your diagonal crosser plans...

Again, you need right, left and both. But with diagonal tiles you need to take into consideration all four quadrants and their combinations. One more thing...if you have diagonal tiles, and you use the inverse diagonal tile like I do, then you need two sets of these, one for each dominant tile (terrain type). All that, just for one terrain type, in addition to your base terrain. By now, either your respect for tileset makers is growing, or your confidence in yourself to make a tileset is falling fast. Or both.

In my example above, I made crossers out of impassible stone and joined those to my height transitions. In that scenario, I used the exact same crosser patters you would use to make smoothing crossers. You can use these same patterns to add extra sand at a grass-lake border, to make overhangs on your cliffs and rock outcrops, or even to simply change the rock type shown on your rock faces. Do whatever you want with your crossers, and be creative.

WIP...