MAKE A TREASURE MAP IN GAEA
Utilise Gaea’s Geoprimitive, Lookdev and Cartography nodes to build a terrain and transform it into a game-worthy map asset
You've seen Nathan Drake hold one, and Arthur Morgan draw doodles on his. Maps are a staple in game art, not only as part of the UI but also as hero props, treasure maps or placeables, helping to drive the narrative. And that's what we're going to create here with Gaea.
First, we'll procedurally generate a terrain and its features, mixing and blending Geoprimitive, Lookdev and Water nodes, before we let Erosion do the heavy lifting into a terrain which we'll turn into a map using the Cartography node, complete with a detour through portals to add textures before building and exporting it all via Output nodes. Once exported, we’ll add some finishing touches to the Cartography export in Photoshop (or your image editor of choice).
When working on a map, it’s worth noting there are a few rules of nature and worldbuilding worth remembering. Lone mountains are generally an anomaly unless you're creating a (sleeping) volcano. Mountains are created by tectonic plates pushing against each other, mixed with volcanic activity. And the sheer scale and pressure of these means we get mountain ranges, not standalone peaks. Even a seemingly lonely mountain will have a mountain range in its vicinity. If you’re creating a river, water will always follow a downward path of least resistance mixed with the pull of gravity. That also goes for rivers running down from lakes with an underground water supply. Also, rivers don't split. They may join, but they generally don't split. A delta is created by the build-up of sand, sediment and other detritus it met along its journey, so it's built from deposits changing the flow of the water, not a river splitting in two. There are no rules without exceptions, of course, but sticking to these basics will help you lookdev your map and terrain.
As for vegetation, did you know that mountains and their surrounding terrains have a wet and a dry(er) side? It's caused by something called prevailing winds. A prevailing wind is the predominant wind direction that will blow onto an area (or terrain). Wet or dry, the part of the terrain facing that wind will feel its effect the most, which in turn will affect anything from erosion to the finetuning of your biomes.
Let’s dive in and get creative!
01 START A NEW PROJECT
Open Gaea and select New Project. Gaea will open by default with a Mountain and Erosion node set to a random seed and a resolution of 0.5. Let's change the resolution first, provided your hardware doesn't mind; a lower resolution will always be faster, but bumping it up a bit will give you better detail. Even though the preview resolution is not the same as the build resolution, setting it to 2K is a reasonable compromise between both, so go ahead and do that in the top menu dropdown, right next to the file name.
02 EASIER NODE NAVIGATION
Next, we'll make node navigation in the node graph view easier. Go to Gaea in the top left, and select Preferences. Then, change Node Style from Filament to Circuit – this will give each node a symbol. So, in addition to the colour identifying type, you'll have an icon or name on the node itself identifying what kind of node it is, like a Mountain Geoprimitive or an Alluvium Erosion node, and so on. Next, we'll set Connection Style to Circuit to get a tidier connector flow. Leave Node Colour to Bright and click OK to save.
03 TWEAK YOUR LIGHTING
On the right-hand side, click the sun icon in the toolbox, and tweak your sun settings for better viewing. In this part of the tutorial, the Sun Azimuth is set to 285 and the Sun Elevation to 46, with the other settings at their defaults. Click the + icon in the node graph view toolbar and name the new tab ‘Textures’. Right-click the existing graph tab, click Rename and name it ‘Terrain’.
04 START WITH THE MOUNTAIN GEOPRIMITIVE
The Mountain Geoprimitive is probably the biggest staple primitive in Gaea, and probably also its unsung hero, as it's so versatile a foundation for all kinds of terrains. In the Mountain Primitive settings on the top right, set its seed to 42899. This will give us the basis for a nice, rugged terrain with a coastline and also a steep cliff as an outlook. Next, right-click the connector between the Mountain and Erosion nodes. Type Fold into the search box, then click Fold and load it.
05 CONNECT THE LOOKDEV FOLD NODE
The Fold node will load connected to the Mountain node. Link it to Erosion by replacing the Mountain connector. Set Folding to 0.18 and Seed to 3090. We're adding the Fold node here because it drastically changes the shape of any terrain. Mimicking terrain folding, it does this by adding slants, breaks and folds to your previous terrain nodes. In our case, we're using it to flatten the existing terrain a little, as well as create some flats and a fledgling coastline for a more varied terrain to place map items on.
06 ADD THE LOOKDEV CARVER
Drag the Carver node into the Terrain view from the node list on the left. This node's job is to make terrains more complex. It does so by adding Erosion Power and Displacement, as well as the angle in which to implement your settings. This is what generates the undulating lines on your terrain. As it's very powerful, we only need a little; set Erosion Power between 20 and 44.
07 ROUGHEN UP WITH ANASTOMOSIS
Next, drop an Anastomosis node onto the Carver node to complement the results, as Anastomosis roughens up the terrain's surface without losing the features we just created. It does that by creating interconnected water flows based on downcutting, ranging from tiny pits to large river channels. We're going to use low settings to make a cleaner coastline in the next node, but still add some detail for Erosion to work of off. Set Impact to 5%, Impact Area to 15% and Influence to 20. Then, set Downcutting to Destructive. It won't be as visible on Carver's lines, but it will have an effect on the steeper slopes of the terrain.
08 ADD A COASTLINE
Even though Gaea has both an Island Geoprimitive and a Zeroedges Adjustment node, many prefer to use the Water nodes Coast and Lakes to tailor their coastlines. Drop a Coast node onto the Anastomosis node, and set Intensity to 25, Beach Size to a small 0.11 and Transition to 0.51 to even out some of the rougher coastal rock areas.
09 USE THE LAKES NODE FOR EDGES
Drop a Lakes node onto the Coast node. We'll use this to generate a large and a few small lakes on the terrain. This node also simulates rainfall on your terrain, so both small pits and larger areas will be filled with water. Precipitation refers to the amount of rainfall on your terrain; set it to 15%. We don't want too many puddles or lakes, so set Small Lakes to 50%. You can tweak the Shore formation settings to enhance your coastline, but we will leave the settings to default for now.
10 ERODE IT ALL
Drop an Erosion node onto the Lakes node. As you can see, it's not the best of looks. The Erosion is there, but it's very rough. We'll fix that: first, set the Seed to 75868. Scroll back up. Set Duration to 20. Even though the recommended setting is around 1, increasing the duration also softens the steep-angled slopes we have and evens out the coastline even more, so 20 it is.
11 EROSION, CONTINUED
Soft rock erodes faster, so set Rock Softness to 50. Set Downcutting to 2.5. Downcutting is good for getting deeper gullies into the terrain, as well as tweaking angled or steep slopes. Go easy on it, otherwise your verticals will look like a super-eroded mess. Also check to see if Aggressive Mode is on. It speeds up erosion processing but can create softer erosion artefacts because of it (but we want those). At this point, it’s also a good time to play a little with your lighting, to see how your terrain looks under different conditions.
12 FINAL TWEAKS
Once you're happy with your terrain, you can add some tweaks to it or bulk it up a little. As the terrain has some really thin edges across it, we're going to bulk it up by using the Shaper Profile node. Drop it onto your Mountain node and connect it to the Fold node. Set Shape between 6.5 and 15%. Your terrain may look very spiky and off, but that's because the nodes need to refresh. You can solve this by clicking the ‘Force a Refresh’ button in the lower right of the node graph view.
13 SMOOTH THE EDGES
Now, let's centre the terrain. Sometimes moving a terrain with a Transform node can create edge artefacts. We'll solve that with a Combiner node using Blur and Transform. Drop a Blur node onto the Erosion node and set it to 0.5. Next, drag a Transform node onto the Erosion node, and check Fill and Mirrored Edges. Set Position to X –3 and Y to –2. Take Blur's output node and put it onto the Transform node's Output. This will automatically create a Combiner node. Set it to Multiply, Ratio to 5, and name it Final (F2).
14 PORTALS AND TEXTURES
When texturing, the Texture node needs to know which terrain node to use as a basis. Right-click Final. Set it to Pin as Underlay. In order to avoid node spaghetti, we're creating a portal, which allows us to connect nodes across views or graphs without visible connections. Drag on Final's Output, right-click and choose Make Portal. Next, click the Textures tab, and create a Texture node.
15 COLOUR AND CARTOGRAPHY
Drag its input out and right-click. Under Portals, select Final to connect the terrain and texture views and set it to C. Still in the Texture view, drop a Satmap node onto the Texture node. You will get a set of gradients in the parameter view. In the dropdown, select Green and set it to gradient 0171. This adds a texture to the whole terrain. Rightclick and add an Output node on it. Next, we'll add a Cartography node to the Texture node. Satmap and Cartography don't affect each other, but that doesn't mean we can't use both outputs.
16 THE CARTOGRAPHY NODE
This node creates map output based on where you plug it into your terrain or texture. Create a Cartography node from the Render options and plug it into Texture's output node. Create a portal on the Lakes node's depth channel, then plug it into the node's water input, and check Water. If you don't want a grid, you can set grid intensities to 0%.
17 BUILD AND EXPORT
It's time to export our terrain, the texture and the map. In the Terrains view, drop the Mesher node from Output onto the Final node. This will export our terrain. Set format to Obj, resolution to 4K, Force Quads, and LOD to the LOD you want. The example uses LOD0. In the texture tab, drop an Output node from Output on both Satmap and Cartography nodes, set both to 16 bit-tiffs, and export to the Build folder. Next, click Build next to the output properties in the Properties tab, set your Build folder, and hit Build.
18 EXPORT ADJUSTMENTS
Gaea may ask if you want to use cached versions. Say no and build from scratch. Even though we got a nice map, it’s too detailed for post-work. Slide the Simplify slider upwards and check the Smoothing checkboxes under it. If you’re working in 4K or higher, you may also want to make the lines thicker by increasing their pixel size. Then re-export. When done, all you need to do is load the file in i.e. Photoshop, and add elements like roads, towns and nature as well as an index and a compass, and you’re done. •