The first Blend mode that we will implement is the Multiply blend mode as seen in Photoshop. Let's begin by modifying the code in our shader first:
- Create a new shader by duplicating the ScreenGreyscale code by selecting it from the Project tab under the Chapter 9 | Shaders folder and pressing Ctrl + D. Once duplicated, rename the script to ScreenBlendMode. Then, double-click on this shader to open it in your script editor.
- We need to add some new properties so that we have a texture to blend with and a slider for an opacity value. Enter the following code in your new shader:
Properties { _MainTex ("Base (RGB)", 2D) = "white" {} _BlendTex ("Blend Texture", 2D) = "white"{} _Opacity ("Blend Opacity", Range(0,1)) = 1}