4 level posterization

Quick shader that posterizes with 4 levels – can easily add more levels by adding another color, threshold, and else if statement.

The way I use it is by creating a mesh instance plane in front of the camera and applying the shader to the plane.

Shader code

shader_type spatial;
render_mode unshaded;

uniform vec4 level1 : hint_color = vec4(0,0,0,1);
uniform vec4 level2 : hint_color = vec4(0.5,0.5,0.5,1);
uniform vec4 level3 : hint_color = vec4(1,1,1,1);
uniform vec4 level4 : hint_color = vec4(1,1,1,1);

uniform float threshold1 	: hint_range(0.0,1.0) = .1;
uniform float threshold2 	: hint_range(0.0,1.0) = .4;
uniform float threshold3	: hint_range(0.0,1.0) = .6;


void fragment(){
	ALBEDO = texture(SCREEN_TEXTURE, SCREEN_UV).rgb;
	float rgb_avg = (ALBEDO.r + ALBEDO.g + ALBEDO.b)/3.0;
	if(rgb_avg < threshold1){
		ALBEDO = level1.rgb;
	}else if(rgb_avg < threshold2){
		ALBEDO = level2.rgb;
	}else if(rgb_avg < threshold3){
		ALBEDO = level3.rgb;
	}else{
		ALBEDO = level4.rgb;
	}
}

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