Rain drops on screen – notexture

RayL019

https://www.shadertoy.com/view/MlfBWr

Shader code
shader_type canvas_item;

#define iResolution 1.0/SCREEN_PIXEL_SIZE
#define iTime TIME
#define fragColor COLOR

uniform sampler2D iChannel0;
uniform float frequency : hint_range(-10.0, 4.0, 0.1) = 0.0;
uniform float size : hint_range(0.001, 0.05, 0.001) = 0.015;

// Author: Élie Michel
// License: CC BY 3.0
// July 2017

vec2 rand(vec2 c){
    mat2 m = mat2(vec2(12.9898,.16180),vec2(78.233,.31415));
	return fract(sin(m * c) * vec2(43758.5453, 14142.1));
}

vec2 noise(vec2 p){
	vec2 co = floor(p);
	vec2 mu = fract(p);
	mu = 3.*mu*mu-2.*mu*mu*mu;
	vec2 a = rand((co+vec2(0.,0.)));
	vec2 b = rand((co+vec2(1.,0.)));
	vec2 c = rand((co+vec2(0.,1.)));
	vec2 d = rand((co+vec2(1.,1.)));
	return mix(mix(a, b, mu.x), mix(c, d, mu.x), mu.y);
}

void fragment()
{
	vec2 u = UV,
         v = UV * 0.1,
         n = noise(v*200.); // Displacement
    
    fragColor = textureLod(iChannel0, u, 2.5);
    
    // Loop through the different inverse sizes of drops
    for (float r = 4. ; r > frequency ; r--) {
        vec2 x = iResolution.xy * r * size,  // Number of potential drops (in a grid)
             p = 6.28 * u * x + (n - .5) * 2.,
             s = sin(p);
        
        // Current drop properties. Coordinates are rounded to ensure a
        // consistent value among the fragment of a given drop.
        //vec4 d = texture(iChannel1, round(u * x - 0.25) / x);
        vec2 v = round(u * x - 0.25) / x;
        vec4 d = vec4(noise(v*200.), noise(v));
        
        // Drop shape and fading
        float t = (s.x+s.y) * max(0., 1. - fract(iTime * (d.b + .1) + d.g) * 2.);;
        
        // d.r -> only x% of drops are kept on, with x depending on the size of drops
        if (d.r < (5.-r)*.08 && t > .5) {
            // Drop normal
            vec3 v = normalize(-vec3(cos(p), mix(.2, 2., t-.5)));
             //fragColor = vec4(v * 0.5 + 0.5, 1.0);  // show normals
            
            // Poor man's refraction (no visual need to do more)
            fragColor = texture(iChannel0, u - v.xy * .3);
        }
    }
    
    // Debug noise function
    //f = vec4(n, 0.0, 1.0);
}
This shader is a port from an existing Shadertoy project. Shadertoy shaders are by default protected under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported (CC BY-NC-SA 3.0) license unless anything else has been stated by the author. For more info, see our License terms.

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von
von
1 year ago

how can we make the drops fall and leave a trace?

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Sina Qadri
Sina Qadri
8 months ago

this is For those who want to use Screen version (for 3D games)
add a Color Rect and scale it as big as possible then add this shader to it
what i changed is make the Ichannel to be a screen texture getter and made the UV work as Screen_UV
by this way it works for 3D games as well without an extra viewport setup.

swift

shader_type canvas_item;

#define iResolution 1.0/SCREEN_PIXEL_SIZE
#define iTime TIME * 0.3
#define fragColor COLOR

uniform sampler2D iChannel0 : hint_screen_texture;
uniform float frequency : hint_range(-10.0, 4.0, 0.1) = 0.0;
uniform float size : hint_range(0.001, 0.05, 0.001) = 0.015;

// Author: Élie Michel
<h2>// Ported by <a href="https://godotshaders.com/author/rayl019/" style="color: inherit;">RayL019</a></h2>// Modified By Sina Qadri
// License: CC BY 3.0
// July 2017

vec2 rand(vec2 c){
  mat2 m = mat2(vec2(12.9898,.16180),vec2(78.233,.31415));
return fract(sin(m * c) * vec2(43758.5453, 14142.1));
}

vec2 noise(vec2 p){
vec2 co = floor(p);
vec2 mu = fract(p);
mu = 3.*mu*mu-2.*mu*mu*mu;
vec2 a = rand((co+vec2(0.,0.)));
vec2 b = rand((co+vec2(1.,0.)));
vec2 c = rand((co+vec2(0.,1.)));
vec2 d = rand((co+vec2(1.,1.)));
return mix(mix(a, b, mu.x), mix(c, d, mu.x), mu.y);
}

void fragment()
{
vec2 u = SCREEN_UV,
     v = SCREEN_UV * 0.1,
     n = noise(v*200.); // Displacement
   
  fragColor = textureLod(iChannel0, u, 2.5);
   
  // Loop through the different inverse sizes of drops
  for (float r = 4. ; r > frequency ; r--) {
    vec2 x = iResolution.xy * r * size, // Number of potential drops (in a grid)
       p = 6.28 * u * x + (n - .5) * 2.,
       s = sin(p);
     
    // Current drop properties. Coordinates are rounded to ensure a
    // consistent value among the fragment of a given drop.
    //vec4 d = texture(iChannel1, round(u * x - 0.25) / x);
    vec2 v = round(u * x - 0.25) / x;
    vec4 d = vec4(noise(v*200.), noise(v));
     
    // Drop shape and fading
    float t = (s.x+s.y) * max(0., 1. - fract(iTime * (d.b + .1) + d.g) * 2.);;
     
    // d.r -> only x% of drops are kept on, with x depending on the size of drops
    if (d.r < (5.-r)*.08 && t > .5) {
      // Drop normal
      vec3 v = normalize(-vec3(cos(p), mix(.2, 2., t-.5)));
       //fragColor = vec4(v * 0.5 + 0.5, 1.0); // show normals
       
      // Poor man's refraction (no visual need to do more)
      fragColor = texture(iChannel0, u - v.xy * .3);
    }
  }
   
  // Debug noise function
  //f = vec4(n, 0.0, 1.0);
}

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Denys
Denys
8 months ago

add this line:
uniform float blur_size : hint_range(0.0,5.0,0.001) = 2.5;

and edit this:
fragColor = textureLod(iChannel0, u, blur_size);

to control blur size

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