Shaders on PointLight2D to customize the light mask, possible ?

[MelPeslier]

Is it possible to right a shader code to alter the texture the light is using ?

I made a shader code to make some wave mask that I want to use on the light, so it mixes with the texture and i can have custom waves of light with it. I'm using lights because I want to use the sdf collisions, occluders and all the related lights features.

The problem is that it's not working, I wrote it into the fragment() and I also tested into the light(), but It doesn't work

Here is the shader code, and the result in the material preview, and the final result is the unaffected light in the scene (that have a fully suarred texture)

Shader code :

shader_type canvas_item;

group_uniforms Waves;
uniform float wave_radius = 0.5;
uniform float wave_outer_line_coefs = 0.05;
uniform float wave_current_radius;
uniform float wave_inner_radius;


float smooth_stroke(float _edge, float _aim, vec2 _width){
	float inner = smoothstep(_edge, _edge + _width.x, _aim);
	float outer = smoothstep(_edge - _width.y, _edge, _aim);
	return outer - inner;
}

void fragment() {
// * Center UV *
	vec2 uv = UV ;
	uv = uv * 2.0 - 1.0;

// * World mask * : Circle visible
	float circle_sdf = length(uv) / wave_radius ; // divide length(...) by  radius / screen.x
	float outer_edge = step(circle_sdf, wave_current_radius); // TODO : make smoothstep
	float inner_edge = smoothstep(circle_sdf, 0.0, wave_inner_radius);
	inner_edge = pow(inner_edge, 0.5);
	float inner_part = min(inner_edge, outer_edge);

// * Outer Line *
	float outer_line_mask = pow( smooth_stroke(circle_sdf, wave_current_radius, wave_outer_line_coefs * vec2(1.0, 0.25)), 2.0);
	float line_fade_out = smoothstep(1.0, 0.75, wave_current_radius);
	float wave_output = outer_line_mask * line_fade_out;
	
	COLOR.rgb = vec3( inner_part + wave_output ) ;

}

Result wanted :

Unaffected scene :

Test using subviewports : #9886 (comment) ( just below first comment)

[AThousandShips]

Is the LIGHT_VERTEX inout not working for your case?

[MelPeslier]

I'll try right now

[MelPeslier]

Left is the light, Right is the sprite

COLOR.rgb = vec3( inner_part + wave_output ) ;
LIGHT_VERTEX.rgb = vec3( inner_part + wave_output );
It doen't do anything, Idon't understand what they give access too, I tried using them to output colors, but it's always 1 as the output for LIGHT_VERTEX.rg, and SHADOW, Do you have any hint on how to use them ?

[AThousandShips]

What do you mean it doesn't do anything? It looks like it gives a shadow in the top right? But I can't help you using it as I don't use it myself, but if you try it out and experiment I'm sure you can figure out how to use it

Or ask in the forums

[MelPeslier]

No the shadow is gived with the occluder up here, doesn't have anything to do with it :)

[AThousandShips]

Then my bad that's the wrong tool for this, mistook your second image for desired results

You should probably use the light() function then to achieve relevant results

[MelPeslier]

I tried using viewports as the original texture, it does work with sprite2D, but still not with lights2D
Sprite using the viewport :

Light2D using the subviewport :

Should light up the scene like this Light2D (this one using a gradient texture):

How does is not use the viewport texture ?

[AThousandShips]

You can't use them for light textures, see:

• Only allow valid types in Decal, Light3D projector and PointLight2D texture godot#88349
• ViewportTexture doesn't work within PointLight2D godot#75868