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Asked By
SesshaNeko
Hello, could you please answer my question? I’ve just started learning shaders. This code creates a spiral, I’d like to lay a sprite on this effect, how can I do that?
shader_type canvas_item;
uniform float StripesNum = 9; //slider[1,10,100]
uniform float StripesAng = 45; //slider[-180,45,180]
uniform float StripesThinkness = 0.5; //slider[0,0.5,1]
uniform float CenterHole = 0.0; //slider[0,0.125,1]
uniform float OuterHole = 1; //slider[0,0.825,1]
vec2 cLog(vec2 z){
return vec2(log(length(z)), atan(z.y, z.x));
}
void fragment(){
float pi = 3.141592653589793;
vec2 p = UV.xy - vec2(0.5, 0.5); // correct to the center of texture
float t = radians(StripesAng);
float c = cos(t);
float s = sin(t);
mat2 m = mat2(vec2(c, -s), vec2(s, c));
vec2 q = m * cLog(p);
//vec2 q = cos(m * cLog(p)+TIME);
float color = float(mod((StripesNum * q.y / (sqrt(2.0) * pi))-TIME, 1.0) < StripesThinkness
|| length(p) < CenterHole
|| length(p) > OuterHole
);
COLOR = vec4(vec3(color),1);
}
Great shader!
Mixing them is relatively easy. To access the texture of the sprite, TEXTURE is used, and to access its UV coordinates, UV is used. I leave a simple example using the functions mix () and texture (), but the possibilities are almost endless. Now if you want to deform the texture of the sprite is different, a few questions back and I answered on a shader to deform a flag. That shader is an example but you can find thousands of pages like shadertoy. It is pure math everywhere. You can also use SCREEN_TEXTURE and SCREEN_UV to access the texture and uv seen on the screen.
Assing to a sprite whit texture:
shader_type canvas_item;
uniform float StripesNum = 9; //slider[1,10,100]
uniform float StripesAng = 45; //slider[-180,45,180]
uniform float StripesThinkness = 0.5; //slider[0,0.5,1]
uniform float CenterHole = 0.0; //slider[0,0.125,1]
uniform float OuterHole = 1; //slider[0,0.825,1]
vec2 cLog(vec2 z){
return vec2(log(length(z)), atan(z.y, z.x));
}
void fragment(){
float pi = 3.141592653589793;
vec2 p = UV.xy - vec2(0.5, 0.5); // correct to the center of texture
float t = radians(StripesAng);
float c = cos(t);
float s = sin(t);
mat2 m = mat2(vec2(c, -s), vec2(s, c));
vec2 q = m * cLog(p);
//vec2 q = cos(m * cLog(p)+TIME);
float color = float(mod((StripesNum * q.y / (sqrt(2.0) * pi))-TIME, 1.0) < StripesThinkness
|| length(p) < CenterHole
|| length(p) > OuterHole
);
vec3 color_final;
vec3 tex=texture(TEXTURE,UV).rgb;
/* YOUR FORMULA MULTIPLY UV */
vec2 uv= UV*color;
/* MIX: */
//color_final=mix(vec3(color), tex, 0.5);
/* MIX IF WHITE = 1: */
//if (color == 1.0)
// color_final=mix(vec3(color), tex, 0.9);
//COLOR= vec4(vec3(color),1); //original
//COLOR= vec4(color_final, 1.0); //mixes
COLOR= texture(TEXTURE,uv); //modify uv to texture
}
