Heightfield Generate

Heightfield Generate

Node Description and Purpose:
The Heightfield Generate node can be used to generate unique heightfield terrain based on a simple but powerful set of criteria. You can generate new heightfields based on fractals built into the node or you can use other shaders to generate height information for the heightfield. Use this for creation of heightfield terrains, especially in cases where you wish to apply heightfield-specific operations such as Erosion. Heightfields are of finite resolution and cover a specific area, unlike procedural terrains which have theoretically infinite detail and can cover an entire planet. However in Terragen 2 heightfields may be optionally rendered with procedural displacement to enhance detail. This is enabled by default.

Node Type: Heightfield Operator

Settings:

• New heightfield: If this is checked the Number of points and Size in metres params are used to set the size and resolution of the heightfield. If this is not checked then heightfield dimensions are taken from nodes connected to the Input node input.
• Number of points: This sets the number of points, or resolution, of the heightfield. This doesn't control the area the heightfield covers, that is done with the Size in metres param.
• Size in metres: This sets the X and Y size of the heightfield in metres. This is different to number of points in the heightfield as set above. Size in metres controls the area covered by the heightfield, whereas Number of points controls the resolution or detail of the heightfield.

Fractal tab

• Feature scale: This parameter sets the average size, in metres, of the features generated in the heightfield.
• Feature steepness: This sets the steepness of the generated features. Larger numbers make things steeper and will also increase the overall height of the features.
• Roughness: This controls the roughness of the generated terrain. Larger numbers are rougher.
• Seed: This number controls the pattern generated by the node. If you use the same number in multiple Heightfield Generate nodes they will all generate the same pattern. The values of the parameters above can change the look of the terrain but the underlying patterns will be the same.
• Random Seed: Clicking this button will randomly choose a new number for the Seed parameter.

• Auto generate: If this is checked the heightfield will regenerate when a project is loaded or when other parameters change. At this time it's recommended that you do not check this parameter.
• Generate Now: Click this button to generate the heightfield.

Additional tabs for Heightfield Generate

• Heightfield Generate - Tweak Fractal Tab

• Heightfield Generate - Use Shader Tab

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