Struggling to cast a uvec4 to vec4

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1

4.3

Hello! Super Shader noob here, likely stuck in the “don’t know what questions to ask” phase. I’m trying to make a shader that references the uint values of a source texture, but I am unsure how to convert that information back to something that can be rendered. Or something of that nature:

shader_type canvas_item;

uniform usampler2D base;

void fragment() {
	uvec4 current_pixel = texture(base, UV);
	uint p_color = current_pixel.r;
	if (p_color > 120u){
		current_pixel = uvec4(0, 255, 255, 255);
	} 
	COLOR = vec4(current_pixel);
}

When the above code is run on any sprite, it returns a solid cyan sprite, when I think it should only return a sprite that is cyan for pixels with a red channel higher than 120, (I primarily am testing it on a red gradient, but have tried others for the same results.) I am also assuming a u8 scale, is that incorrect, perhaps? I’ve seen recommendations to divide the result by 255.0 or 4294967295.0, but both of those rendered the sprite blank…

I’m at a loss for what could even be occurring, and I have hit the limit of my language in asking intelligent questions. Any insight would be appreciated.

2

Are you positive that your texture uses unsigned integers? It’s much much more common for textures to use float values of 0-1.
I’d try just converting all the variables to floats and see if that fixes your problem.

3

One thing that is very helpful when working with shaders is converting StandardMaterial3D to a ShaderMaterial and then copying the parts you need.

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