Godot color replacement shader not working

[NoodleMeanie]

Godot Version

4.2

Question

In my Godot game I have a player sprite. With a shader I’m trying to make it so one color of the sprite will be changed to whatever I need it to be. In my shader it only works when I try to change the color black, but I am trying to change the color of the orange (not the light orange). I’ve tried looking at many tutorials but none of them work.

shader_type canvas_item;

uniform vec4 og_color : source_color;
uniform vec4 new_color : source_color;

void fragment() {
	vec4 curr_color = texture(TEXTURE, UV);

    // Define a threshold for the comparison
	if (COLOR == og_color){
		COLOR = new_color;
	}
	else{
		COLOR.rgb = curr_color.rgb;
	}
	
}

[game_devzer]

if (curr_color == og_color){
COLOR = new_color;
}

[NoodleMeanie]

Yup, tried that.

[game_devzer]

The shader is working. Did you try to attach a material with the shader to sprite2d?

[game_devzer]

If your sprite2d is a child of node2d to which the shader is attached, you can try enabling “use parent material” in the sprite2d settings.

[game_devzer]

There is another problem with my version of the engine 4.2. When I reload the project, the engine seems to forget what colors were selected in the shaders parameters, despite the fact that they are displayed reliably. Only when I pick the og_color color again the shader start working as expected.

[NoodleMeanie]

I don’t think so. The only thing I have done is material: New shader material, and then added the shader. It is an animated sprite though.

[game_devzer]

Your problem may be that you are trying to compare floating point numbers: vec4.

The Floating-Point Guide - Comparison

You can try converting curr_color and og_color to uvec4 or do something else.

shader_type canvas_item;

uniform vec4 og_color : source_color;
uniform vec4 new_color : source_color;

void fragment() {
	vec4 curr_color = texture(TEXTURE, UV);

    // Define a threshold for the comparison
	uvec4 uint_curr_color = uvec4(round(curr_color * 255.0));
	uvec4 uint_og_color = uvec4(round(og_color * 255.0));
	if (uint_curr_color == uint_og_color){
		COLOR = new_color;
	}
	else{
		COLOR = curr_color;
	}
	
}

[NoodleMeanie]

I found the issue. The problem was that I was using HDR 2d, and that ruins some shaders.