Masking color with a packed image

Help
, , ,
1

Godot Version

4.6.1

Question

I’m trying to write a shader that uses a packed image to mask colors. I have a packed image and I want to use each channel of the image to create a mask that I can set to a specific color.

Something like “color_1” would correspond to everything masked in the red channel, “color_2” for the blue, and “color_3” for the green. I’m used to working in Unreal, where I could use mask and lerp nodes to control this, but I haven’t figured out how to do this in Godot. I tried recreating that logic with:

vec3 color = inverse_lerp(color_1, (inverse_lerp(color_2, color_3, texture(mask_image, UV).b), texture(mask_image,UV).r);

But that throws an error that the “inverse_lerp” function doesn’t exist. I found it in the documentation here but I’m definitely using it wrong. I’m super new to Godot so any advice or information would be incredibly helpful!

2

That documentation is extremtly old (Godot 3.0), here is the correct documentation:

3

I was able to figure it out! for anyone looking for a quick way to do this, here is my code:

shader_type spatial;

uniform sampler2D mask;

void fragment() {
	vec3 color_1 = vec3(1,0,1);
	vec3 color_2 = vec3(0,1,0);
	vec3 color_3 = vec3(0,0,1);
	vec3 color = texture(mask,UV).rgb;
	
	ALBEDO = mix(mix(color_1, color_2, color.r), color_3, color.g);
}