Micro Exporter

Node Description and Purpose:
The Micro exporter can be used to export terrain geometry. Unlike exporting a heightfield using the Micro exporter allows you to export procedural terrains as well as displacement and overhangs etc. The Micro exporter can export geometry (polygons), normals and texture coordinates. It supports TGO, OBJ and LightWave LWO2 formats.

Primarily the Micro exporter is used in conjunction with a Render node to export geometry generated during a render. The Camera used for rendering partly defines the area of the terrain that will be exported. You can also use the Near distance and Far distance parameters to limit the area of terrain exported. Only geometry within the view of the camera is exported. Backfacing polygons, which are those facing away from the camera, are also exported.

The Micro exporter basically works by exporting the micropolygons generated by the renderer. This has a few implications. It means the detail setting of the Render node the exporter is connected to controls the size of the polygons generated. Lower detail will generate a coarser mesh. Polygons also get larger the further they are from the camera.

The easiest way to create a Micro exporter is to use a Render node. Follow these steps:

1. Go to the Sequence/Output tab of the Render node.
2. Click the Assign button (green plus icon) to the right of the Micro exporter parameter.
3. Choose "Create new micro handler" from the menu which pops up.
4. Choose "Micro exporter" from the submenu.

You will also need to check the Micro exporter checkbox to have the geometry exported during rendering.

Note that the Lwo micro exporter which in the "Create new micro handler" submenu is an older node which remains for compatibility reasons and is deprecated. You can export LWO files from the Micro exporter and should use it instead.

Node Type: Other

Settings:

• Normals: Check this checkbox to export normals for the geometry.
• Texture coords: Check this checkbox to export texture coordinates (UVs) for the geometry.
• Nearest distance: This parameter sets the distance from the camera where geometry starts to be exported. The default value is 0 which means geometry is exported right from the camera position. If you set this to 1000 then only parts of the terrain 1000m and more from the camera will be exported.
• Farthest distance: This parameter sets the furthest distance from the camera that geometry will be exported. Parts of the terrain beyond this distance are not exported.
• Filename: This parameter specifies the file that the exported geometry will be saved to. The extension of the file sets the format which is used. For example to export an OBJ file you need to add ".obj" to the file name. This holds true even if you use the Choose File button to choose the file, as the file dialog doesn't have a format popup. These are the extensions you should add for the supported formats:
  • ".tgo" for Terragen TGO format
  • ".obj" for OBJ format
  • ".lwo" for LightWave LWO2

A heightmap or heightfield is an array of height values, usually in a grid which describe the height at specific points in a defined area. Heightfields are used to represent real-world and virtual terrain in a specific, easily converted format. Most heightfields can be represented as simple image data in grayscale, with black being minimum height and white being maximum height.

In general a “procedure” is a series of steps that should result in a specific and reproducible outcome. In Terragen 2 a “procedural” is a mathematical function describing output which may be visualized and sampled to create anything from terrain to clouds.

Literally, to change the position of something. In graphics terminology to displace a surface is to modify its geometric (3D) structure using reference data of some kind. For example, a grayscale image might be taken as input, with black areas indicating no displacement of the surface, and white indicating maximum displacement. In Terragen 2 displacement is used to create all terrain by taking heightfield or procedural data as input and using it to displace the normally flat sphere of the planet.

A single object or device in the node network which generates or modifies data and may accept input data or create output data or both, depending on its function. Nodes usually have their own settings which control the data they create or how they modify data passing through them. Nodes are connected together in a network to perform work in a network-based user interface. In Terragen 2 nodes are connected together to describe a scene.

A parameter is an individual setting in a node parameter view which controls some aspect of the node.

Deprecated items are still supported and available to use but their use is not recommended. Such items will be removed at some point in the future. In most cases an alternative is recommended and that should be used instead.