Displacement Shader to Scalar

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Node Description and Purpose:
The Displacement shader to scalar node extracts the displacement generated by the connected shader, and returns the dot product (inner product) of that displacement vector and the current normal. Effectively this is the amount of displacement in the direction of the current normal. It may be positive or negative.

In general, shaders may displace in any direction, so displacement is a vector. However, most of the time when you want to extract displacement for use in other functions you expect a scalar value. Most shaders displace along the normal, so by returning the dot produce of the normal and the displacement vector, this node produces the displacement value you would typically expect.

See also: Displacement Shader to Vector


Node Type: Function


Settings:
This node has no other settings apart from the Input node.

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.

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

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 vector is a set of three scalars, normally representing X, Y and Z coordinates. It also commonly represents rotation, where the values are pitch, heading and bank.

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.