My Shader is making my pixel art blurry

[AmongGhosts]

Godot Version

v4.4.1

Question

Shaders continue to be the absolute bane of my existence. I’m trying to replicate what is shown in the below two videos in Godot. There is a Youtube Shorts version and a longer video. The TLDR is dynamic coloring at runtime via some kind of post-processing shader (I think I’m getting all those terms right).

Short
Full Video

The issue I’m running into is that the shader makes the images blurry. I have a source, a color map, and a color lookup table, which I have pasted below.

When I set a Sprite’s texture to one of these, it appears as clear as in the above images. I made a canvas shader for the next step though and it appears blurry, as shown below.

This is the entire shader:

shader_type canvas_item;

uniform sampler2D lookup_texture;

void fragment() {
	COLOR = texture(lookup_texture, UV);
}

It seems like it’s appearing as though the texture filter were set to linear instead of nearest, but I can’t seem to find a way to confirm or deny that, let alone fix it. Any help would be greatly appreciated.

[sixrobin]

Hi,

Try specifying the nearest filtering in the sampler declaration:

uniform sampler2D lookup_texture: filter_nearest;

[AmongGhosts]

This worked, thank you. Do you just know that from experience, or is a good place in the docs to find something like that? I wasn’t able to find any good sources from googling.

[sixrobin]

I believe I’ve learnt that on this page: Shading language — Godot Engine (stable) documentation in English, which is just a huge list of Godot’s shader language features. I obviously did not read it fully, but I’m used to documentations like this so I guess I just looked for the filtering info when I needed it for the first time

[FencerDevLog]

I have a video tutorial on this topic. In it, I explain the use of parameters for sampler2D in shaders, so it might be useful.

Godot 4: Texture filters (shader tutorial)