UE4 – RemapValueRange Node

Software:
Unreal Engine 4.24

Having to remap a value range is very common in designing shaders, whether it’s to perform a traditional “levels” operation on a texture, or use just a specific range of values in a float input.
The RemapValueRange node let’s us do just that. this node has 5 inputs:

  1. Input: The input value
  2. Input Low: Input mapping range minimum
  3. Input High: Input mapping range maximum
  4. Target Low: Output range minimum
  5. Target Height: Output range maximum

Mono Noise examples:

  1. The original noise pattern:0
  2. Mapping input 0 -> 1 to output 0 -> 1 obviously has no effect:1
  3. Mapping input 0 -> 1 to output 0.3 -> 0.7 reduces the pattern contrast:2
  4. Mapping input 0.3 -> 0.7 to output 0 -> 1 increases the pattern contrast:3
  5. Mapping input 0 -> 1 to output 1 -> 0 inverts the pattern:4

In this example RemapValueRange nodes are applied to a texture’s individual color channels to increase contrast (Levels):
> Note that this operation can be performed using a simpler graph by using float3d adding and multiplication operations on the texture color (this will be a subject for a different post)
> Note that a different remapping operation can be performed on each color channel of a texture to adjust its color balance.

Before the value remapping:5

After the value remapping tha value in each channel 0.1 -> 0.9 to 0.0 to 1.0:6

The same operation performed by multiplication by 1.2 and subtracting 0.1:7.jpg

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