Perlin 4D Scalar

Noise

Perlin 3D Scalar

Perlin 4D Scalar

Smooth Voronoi 3D Cell Colour

Smooth Voronoi 3D Cell Scalar

Voronoi 3D A Vector

Voronoi 3D B Vector

Voronoi 3D Cell Colour

Voronoi 3D Cell Scalar

Voronoi 3D Diff Scalar

Perlin 4D Scalar

Overview

This node generates Perlin noise and outputs the noise value as a scalar. The output value ranges between -0.5 and 0.5. This node has a Time parameter which allows the noise pattern to change over time. Here is an example of the noise pattern generated by the node:

Rendered top view of Perlin 4D scalar noise pattern.

Render perspective view of the same Perlin 4D scalar used for displacement.

This node requires a Get position, Get position in geometry, or Get position in texture function node to be assigned to its Main input so that the current render state knows where a sampled point is located in texture space. In the example below, the current frame number is converted to time based on the number of frames per second, then assigned to the Time parameter.

Node Network view of Perlin 4D Scalar with required node for position in texture space, and optional nodes to drive scale and seed values. In this example, the frame number is converted to time, then assigned to the Time paramater.

Settings:

• Name: This setting allows you to apply a descriptive name to the node, which can be helpful when using multiple Perlin 4D scalar nodes in a project.
• Enable: When checked, the node is active, and when unchecked the node is ignored.
• Time: The shader or function nodes assigned to this setting, sets the time value.
• Scale: This setting controls the overall scale of the noise pattern generated. Increasing the scale value makes it seem like the cells in the noise pattern are larger.
• Seed: The setting controls the noise pattern generated. Each seed value generates a slightly different pattern.

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 scalar is a single number. 1, 200.45, -45, -0.2 are all examples of scalar values.

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

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 shader is a program or set of instructions used in 3D computer graphics to determine the final surface properties of an object or image. This can include arbitrarily complex descriptions of light absorption and diffusion, texture mapping, reflection and refraction, shadowing, surface displacement and post-processing effects. In Terragen 2 shaders are used to construct and modify almost every element of a scene.