Palette Filter For 3D and 2D
To add Just create a canvas layer with a sprite then attach the shader into it. The gradient should be a horizontal gradient texture, you can download one from the internet or use the gradient texture from godot. P.S.: You can get the palletes from Lospec.com
Have fun! 🙂
Shader code
shader_type canvas_item;
uniform bool flip ;
uniform sampler2D gradient : hint_black; // It can be whatever palette you want
void fragment(){
vec4 col = texture(SCREEN_TEXTURE,SCREEN_UV);
float lum = dot(col.rgb,vec3(0.2126,0.7152,0.0722)); // luminance
col = texture(gradient,vec2(abs(float(flip) - lum),0));
COLOR = col;
}
This is pretty nice. The only thing I’d mention to anyone is that you need to put a texture (even the godot icon is fine) on the sprite and make it the size of your viewport to work. I figured it out pretty easily, but just in case someone else can’t.
Also having the flip parameter for palettes that have have the lighter colors on the left was very convenient.
hey! just letting you know, this shader is really neat and i’ve used it in a game of mine, if that’s ok! (it can be found here if you want to have a look)
Is it possible for this to be used on a ViewportContainer as a post-processing effect?
Had to change SCREEN_TEXTURE to TEXTURE, and SCREEN_UV to UV:
(Now mind you I have no idea what I’m doing, it just worked for me)
Also the flip feature is amazing
The only difference is your shader will change your sprite directly
starting with Godot 4, you’ll need to reduce the bit depth to achieve an effect equal to what’s shown in the screenshots, and it will not adjust automatically to the size of the palette.
create a bit_depth uniform variable for changing the bit depth.
and then, after creating the lum variable, reduce it by the bit depth.
then just apply it to the color as normal
in Godot 4, this works really well as a post-processing shader by applying it to a SubViewportContainer, containing a SubViewport
you can also easily make this sprite-based (which is the approach I used to get different palettes for each sprite) by swapping SCREEN_TEXTURE and SCREEN_UV for TEXTURE and UV respectively, and applying the ShaderMaterial to a Sprite2D node
and maybe this isn’t news but you can use a GradientTexture1D in place of a .png texture, really makes things easier