Terrains in Torque 3D - A Pocket Guide

Welcome

Environment art is one of the most important visual aspects of any 3D game, and this importance increases as the overall detail of the game increases. The higher the detail level of your environments, the harder it will be to maintain consistency visually, as players will notice errors in texturing or modelling that in a lower detail setting would be overlooked. It is for this reason that many developers have such a hard time getting their environments to look exactly the way they envisioned. It's also one of the reasons some people have trouble with terrains. There is nothing more obvious to the player (most of the time) than the landscape they are acting in, and when it goes wrong, it goes horribly wrong. This guide will hopefully show some useful tricks to getting the most out of your terrains.

Introduction

Making terrains for any game requires that the designer actually understands some basic geological processes, such as erosion, vulcanism, sedimentation, stratification, etc,. There are plenty of resources online for learning this stuff, so I won't go into any detail regarding these. I'll continue on the assumption that anyone reading this guide will also have the ability to use Google.

Before we begin, I want to ask a very important question: Do you actually need a terrain? This may seem a no-brainer to some, but the fact is that we don't actually need a terrain for much of what we do. In many cases it will be simpler and more efficient to make sections of terrain. Maybe a canyon with a river flowing through it and a path that runs alongside the river. I don't need a terrain file to make that scene. I need cliffs, ground and that's it. I could use a mesh object as a terrain, and simply wall myself into a path by placing cliffs and rocks.

There are times when a terrain is good, and needed. Skyrim wouldn't work if it was all tiny sections with no vistas. That being the case, let us get to the good stuff.

I've created a heightmap and matching diffuse map to be used with this guide. Grab the height and diffuse maps here.

Tools

The tools available to us with which to create our terrains makes for a very short list. L3DT, World Machine 2 and GeoControl 2. These are all excellent programs, but they all have their own distinct strengths and weaknesses.

L3DT makes fantastic textures, and the Design Map is a veritable gift from the gods. But it's terrible at geological processes.

World Machine 2 is probably the most powerful tool around for geological effects, and in its ability to be crafted to the finest detail. But it is also the tool with the greatest learning curve.

As mentioned, I haven't used GeoControl 2, so my opinions here will mean absolutely nothing, but as I understand it GeoControl 2 is great for making renders, but isn't optimal for use in Torque.

Some kind of image editing software will most certainly be needed, as you'll be texturing and tone matching and you'll need to play with pixels at some stage. I use Photoshop 9 but GIMP is also quite popular as it's free

Methods

I have something of an unorthodox method of importing my heightmaps into Torque, and I'm not 100% sure it's the best method, but it works for me, and that's what matters. Here's what I do:

1. Create the terrain heightmap in World Machine 2 or L3DT (well, both)
2. Export to Torque (./game/art/terrains)
3. Create the diffuse map (the low detail colour map) in WM2 or L3DT (or both)
4. Export that to Torque (./game/art/terrains/example)
5. In the T3D editor, select File > Import Terrain Heightmap (set meters per pixel to 1)
6. Inside the Terrain Painter create a new material called newOverlay and navigate to the example folder that houses your new diffuse map, and select it. Now set its size to the resolution of the diffuse map, ie: 1024 if it's a 1024x1024px image, 2048 for a 2048x2048px image
7. Apply and select.

Now, you'll probably have to set the terrain square size to 4 so that a) the texture fits snugly over the terrain without tiling, and b) to get the right altitude scale. Alternatively you could have set the meters per pixel to 4 at the import stage, but I want you to see what happens with the setting at 1. If there are steps in the terrain caused by resizing the heightmap simply smooth the terrain a few times to get something that works for you. You should be seeing a very nice overall colour and distant detail, but the ground at your feet will be lifeless, low-res and ugly.

Texturing

And now for the fun part. We're in a desert here (assuming you're using the maps I provided), so we need to understand a little about desert terrains and geological processes. As you know deserts have very little water and vegetation, but for us this isn't what differentiates a desert from a temperate environment. What does is the rock and soil types. Because deserts aren't subjected to water erosion as greatly as a temperate environment is, the whole shape of the terrain is different. The processes at work here are almost entirely wind erosion. Other things like slope stability come into play, and you have large rocks breaking away from cliffs, before being broken down further into pebbles and sand.

So what we'll need here is 3 textures. Rock (for the cliffs), sand and pebbles. I paint the rock layer first, because in the real world sand sits on top of the rock. Not the other way around. That goes over the entire terrain, so you can actually set this when you create newOverlay. You'll need 2 versions of the rock texture. One for the standard texturing (projected onto the map from above) and one for a side projection. So, duplicate the newOverlay to newOverlayCliff and newOverlayCliffSide. Keep the settings for both identical, but check the 'use side projection' option for newOverlayCliffSide.

We're only going to make one sand and one pebble texture for this example, and each texture will use the same diffuse map. With the same diffuse size. The only difference will be in the detail and normal maps used for each. So, to business.

I like to paint the sand texture first, as pebbles are heavier and will settle lower on the terrain than the sand, and you want a transition zone between the cliff and pebbles textures. There will be times (even on this map we're working on) where several other sand and pebbles textures will be used as a manual brush, just to tidy things up later on. But that's way down the track. So with this in mind, let's go ahead and set up our rules for painting the textures onto the terrain. That means brushes.

Brushes

The brush tool within Torque is actually a very sophisticated device. I should point out that what you're doing with the brush is actually painting a 2d texture. The result being the _basetex.dds image that resides in your terrains folder. When sculpting in the terrain editor (as opposed to the terrain painter) you're altering the heightmap. At least, that's the way I understand it. It's possible that I'm mistaken in these processes, but if that's the case our beloved community will set me on the right path. :)

Okay, so let's start with the slope ranges for these textures. Here are my typical settings:

Rock is 0 to 90 degrees,
Sand is 20 to 40
Pebbles is 0 to 20

You'll probably end up preferring slightly different settings, and if it works that's just fine. In the end these settings need to adapt to whatever terrain is currently active. Now, go ahead and start painting a small section of terrain. Choose a section that incorporates all slopes used, ie., 0 to 90 degrees. That way you save a lot of time experimenting with different texture sizes and files. It's rare to find the perfect match on the first go. But there is a way to ensure the minimum time wastage.

Colours

Landscape texturing is no less an art form than painting with oils on canvas. What this means is that basically, if you can't paint a landscape on canvas or other physical medium, then your terrains in Torque will suffer. That being said however, if you can get the colours of your terrain working right, then the overall presentation will be much improved.

Rock and pebbles need to be the same colour, and may need to be the same tone. I mean, the pebbles are just parts of the rock after all. Sand is a little different because of the composition of the rock. Most rocks are made of several different types. That is to say, rock that erodes into sand will erode into different types of sand. All weighing differently and reflecting light differently. Generally speaking though, sand is generally the same hue as the rock, but with a lighter tone. Pebbles need to be the same colour and tone as the rock however. But because we're using the same diffuse texture with this map ( I don't always) we don't need to concern ourselves with texture colour and tone here. We will need to consider light though, so the sun needs to be set up to compliment the terrain. That falls outside the scope of this guide however, so I won't go over that.

In fact, I believe we're pretty much done here. There are many, many things I could talk about in detail, but those things would only make this process more complex and harder to follow. Hopefully this little guide will help you to better understand what's going on in Torque with terrains. At the very least I would hope that you now know something that you didn't before reading this guide.

Fin

Thanks for taking the time to read through this. Please post your results below. I love seeing other people's worlds. Now have at it!

Dan