The Multiply family of nodes allow you to multiply the colour/scalar/vector coming into the Main Input by the color/scalar/vector coming into Input 2. The multiplication is component-wise, for example with a colour :
Main Input.red multiplied by Input 2.red
Main Input.green multiplied by Input 2.green
Main Input.blue multiplied by Input 2.blue
The following example illustrates that when a colour value from the Main Input is multiplied by the value 1 from Input 2 the colour remains the same, but when multiplied by values less than 1 the surface colour darkens, and when multiplied by values greater than 1, the surface colour brightens. Visually speaking, the maximum value displayed can not exceed 1.0 per colour component (RGB) which would result in a white pixel when all three colour components have a value of 1.0. Mathematically speaking, the precise value can be stored in an EXR file.
In this example, the value assigned to Input 2 is 0.5, which results in a colour value that is half as bright as the source colour value from the Main Input.
In this image, each of the colour component values assigned to Input 2 are different, and some are greater than 1.0. This results in an overall colour value that is brighter than the source component colour value from the Main Input. This technique can be used to tint the colour values of a surface, such as changing the leaves of a tree from green to brown..
If a shader or function nodes are not connected to Input 2, the Main Input passes through to the Output.
If a shader or function nodes are not connected to the Main Input, a value of 0, or black, is passed through the node.
All nodes in this family have only one setting, which lets you assign a shader or function nodes for Input 2.
- Name: This setting allows you to apply a descriptive name to the node, which can be helpful when using multiple Multiply Colour nodes in a project.
- Enable: When checked, the node is active and the multiplication operation will take place. When unchecked the colour values assigned to its Main Input, if any, are passed through, otherwise a value of 0 is passed through.
- Input 2: The values from the shader or function nodes assigned to this setting are used as the multiplier to the Main Input values. When nothing is assigned, the Main Input values, if any, are passed through. If the Main Input is unassigned, the output from the node is 0.
A scalar is a single number. 1, 200.45, -45, -0.2 are all examples of scalar values.
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.
A single element of an image which describes values for color and/or intensity, depending on the color system which the image uses. Groups of ordered pixels together form a raster image.
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 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.