Build-in effects - Subtract

Last edited 2026-02-27

This effect decreases the brightness of the image by subtracting the color values of the top layer to the base layer.

Input data:

• Self (Main texture of the object/layer, depending on where you apply the effect; contains information about Red, Green, Blue, Alpha)
• Background (Second texture that contains information about Red, Green, Blue, Alpha* pixels that are underneath Self)

Output data:

• Render (Red, Green, Blue, Alpha colors that will be displayed on the screen)

Example written in pseudocode:
load float4 Self;                                        // LOAD Self texture
load float4 Background;                                // LOAD texture underneath Self texture

float4 Render;                                        // Create an empty variable

Render.rgb = Self.rgb - Background.rgb;                // Assign the result of subtracted Self and Background to the colors R, G, B
Render.a = Self.a;                                        // Assign the Alpha color from Self to Alpha

return Render;                                        // Return the Render

Examples of recreation effects created by the community:

1. Subtraction (Background) by Foxioo; It does the same shader but has more options for modifying the color output and has a port for more Runtime.
2. Subtract (Photoshop) by NaitorStudios; It does the similar shader.

The meaning of colors in the Type column:

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