A Simple First Megatexture
So now that you've made A Simple First Terrain, no doubt you'll want to apply a MegaTexture to it! This MegaTexture won't be as detailed or as attractive as an advanced MegaTexture, but will demonstrate the basics of creating a Surface Tree, assigning textures, and compiling it all into a working MegaTexture file.
For this tutorial you must:
- Have a terrain model UV-mapped in the 0-1 range (covered in the simple first terrain tutorial)
- Have access to some tiling textures. TODO: Link to MegaTexture media!
If you don't have either of the above things, you are not ready to do this tutorial!
This tutorial covers:
- How to set up a MegaTexture material
- How to create a Surface Tree
- How to add texture nodes in the Terrain Editor
- How to render and compile a full MegaTexture
This tutorial does not cover:
- How to use Blender/Maya/Lightwave/ZBrush/Mudbox/3DSMax/Photoshop
- How to create tiling textures or heightmaps
- Anything complicated
Assigning a Working Material
Use your preferred modelling package to assign the material name to your mesh.
Creating a Caulk Hull
Since maps must be leak-free/sealed, maps with terrain must have a caulk hull to ensure this is the case.
In this case, since the terrain is 32768 units long and wide, the caulk hull should also be the same dimensions. The caulk hull is quickly created from a brush 32768 units long, 32768 wide and 16384 units tall, which is then hollowed. The brushes are also assigned the 'editor/noimpactcaulk' texture, which prevents gunshots and projectiles from hitting the surfaces of the hull (they simply disappear instead.)
Setting The Terrain
The mesh must be triangulated before it is exported as an .OBJ, and saved as models/terrain/simpleterrain.obj. At this stage, a texture is not necessary, and can be set later.
Terrains are set up in the Terrain Editor, accessible via .sft) that contains all the information about the terrain, including roads, stamps, and detail texture information that MegaBuild needs to generate a Megatexture.. This tool creates a Surface Tree file (
To set the mesh to the map, first press 'Begin Editing' at the bottom of the Terrain Editor window. Thenon the left-hand pane and create a new Tree via the menu. This creates a Root node on which all the terrain information resides. Clicking on the Root node allows a model to be specified - set to the name of the terrain mesh, in this case . Press to confirm and the terrain should appear in the 3D view, with the red placeholder material.
At this point you may add a player spawn, an atmosphere, and compile the level to check the terrain. However, since there is no material set, there will be rendering issues.
You may find the 3D terrain is partly covered or obscured by the base of caulk hull. This can be fixed by moving or resizing the caulk hull so it contains the terrain properly.
Assigning a Material
It is not possible to assign materials to terrain meshes in EditWorld, you must do this process in your modelling application.
For testing purposes, terrain meshes are often assigned a temporary material until they are in a state that they can be textured properly. Traditionally, this has been one of the existing materials in the game, such as concrete - textures/concrete/concrete10 (although any valid material will work.)
Due to an oddity with the OBJ format, the material name textures/concrete/concrete10 is not valid inside an OBJ file. Instead, the material should be named textures__concrete__concrete10, where the slashes are replaced by double underscores (single underscores will not work!).
Setting the mesh material differs between modelling packages. However, since OBJ files are text, they can be manually edited with a text editor instead of using the modelling application. The OBJ will contain a line (often about halfway through) starting with usemtl followed by an arbitrary texture name. This line should be replaced with usemtl textures__concrete__concrete10 and the file saved.
If you are using Lightwave, 3ds Max, or Maya, you should not have to text-edit any files, just set the material name in the relevant section of the material editor.
editWorld can then be told to reload the OBJ (now with a proper material declaration) via Misc -> Reload -> Models or clicking the "Reload Models" button.
Instead of using the concrete texture, you can use one of the existing Megatextures. For example, to use Area22's megatexture, simply set the mesh's material name to megatextures__area22.
The map and terrain are now in a state that they can be used for level design, however difficulty can arise ensuring the structures in the level fit to the terrain.
This can be countered using editWorld's export tool, which exports map geometry for importing into the modelling package alongside the terrain. This can be done by selecting the geometry to export (such as a building or a reference, located anywhere in the map), and pressing models/export.obj.. This writes the geometry to
The exported geometry can then be used as a template to modify the terrain accordingly - such as flattening areas of land to fit buildings, cutting holes for entrances of simply adding more detail. The modified terrain mesh is then saved for further work in editWorld.
Most often, terrain vertices are snapped to the corners of buildings and structures, such that the terrain faces now covered by the building can be deleted. This allows for buildings to sink into the terrain, and lead into underground areas of the map.
This process of refinement is repeated many times throughout the life of the map, ensuring the terrain precisely fits the map geometry.
When working with terrained maps, most level geometry is stored in separate References to allow for easy editing.
You've now created a map with your very own MegaTexture!
Terrain Mesh UVs
If you find your MegaTexture is not displaying correctly, it may mean your mesh UVs are incorrect. Consult your modelling package to find out how to reset or unwrap the UVs on the terrain mesh.
Terrain model UV coordinates are expected to be inside the 0.0-1.0 UV range. If they are not, you may find that your terrain flickers or stretches when compiled into the map. If you are experiencing these problems, try a simple Planar Map from above, to project UV coordinates down onto your terrain mesh. (Blender instructions: select all the UV faces, hitand select 'Unwrap')