An LUT or Lookup Table is a way of mapping input values to output values via sampling a [[StaticTexture3D_(Component)|3D Texture]]. This 3D table of values allows for any arbitrary function to be applied to an input.
|SecondaryLUT|{{RootFieldType|AssetRef`1|[[Type:Texture3D|Texture3D]]}}|TypeAdv12=true|A secondary 3D texture to use to lerp between
|Lerp|Float|
|UseSRGB|Bool|
|Lerp|Float|Allows blending from the first LUT (0) or the secondary LUT (1)
|BlendMode|BlendMode|
|BlendMode|BlendMode|
|Sidedness|Sidedness|
|Sidedness|Sidedness|
Line 33:
Line 36:
<!--T:3-->
<!--T:3-->
== Usage ==
== Usage ==
An LUT is commonly constructed via 2D slices of a [[StaticTexture3D_(Component)|3D Texture]]. These slices represent XY planes of incremental Z coordinates ranging from 0 to 1. This can either be packed into a single 2D image, or imported as multiple 2D images in a folder where each slice is alphabetically organized.
Currently the maximum packed 2D image that the importer detects as a valid LUT is 1024x32. In this orientation there are 32 total cells arranged as 32x32 pixel sub images. A 1:1 mapping LUT which simply maps its inputs directly to the same value on its outputs is shown below which demonstrates the coordinate system:
* The '''Red''' channel increases constantly from 0 to 1 from left to right within each cell and repeats.
[[File:LUT_BaseLinear_RED.png|center|alt=Linear LUT Red Channel|Linear LUT Red channel|thumb|800x800px]]
* The '''Green''' channel linearly increases from the top to bottom.
[[File:LUT_BaseLinear_GREEN.png|center|alt=Linear LUT Green Channel|Linear LUT Green channel|thumb|800x800px]]
* The '''Blue''' channel increases step wise within each cell itself, the first cell being all 0, and the last cell is all 1.
[[File:LUT_BaseLinear_BLUE.png|center|alt=Linear LUT Blue Channel|Linear LUT Blue channel|thumb|800x800px]]
The mapping function of an LUT takes an input RGB value and then samples the 3D Texture at that corresponding coordinate to find the output RGB value, using the [[StaticTexture3D_(Component)|3D Texture]]'s [[Type:TextureFilterMode|Filter Mode]] and [[Type:TextureWrapMode|Wrap Mode]] to resolve how intermediate values work.
An LUT or Lookup Table is a way of mapping input values to output values via sampling a 3D Texture. This 3D table of values allows for any arbitrary function to be applied to an input.
If true, integrating this asset (e.g. processing procedural assets) gets higher priority than assets with this flag off. An example is user laser procedural meshes.
An LUT is commonly constructed via 2D slices of a 3D Texture. These slices represent XY planes of incremental Z coordinates ranging from 0 to 1. This can either be packed into a single 2D image, or imported as multiple 2D images in a folder where each slice is alphabetically organized.
Currently the maximum packed 2D image that the importer detects as a valid LUT is 1024x32. In this orientation there are 32 total cells arranged as 32x32 pixel sub images. A 1:1 mapping LUT which simply maps its inputs directly to the same value on its outputs is shown below which demonstrates the coordinate system:
Linear LUT
The Red channel increases constantly from 0 to 1 from left to right within each cell and repeats.
Linear LUT Red channel
The Green channel linearly increases from the top to bottom.
Linear LUT Green channel
The Blue channel increases step wise within each cell itself, the first cell being all 0, and the last cell is all 1.
Linear LUT Blue channel
The mapping function of an LUT takes an input RGB value and then samples the 3D Texture at that corresponding coordinate to find the output RGB value, using the 3D Texture's Filter Mode and Wrap Mode to resolve how intermediate values work.
