CRT with variable fisheye

CRT shader with variable fisheye effect.

Shader code
//based on https://godotshaders.com/shader/crt-shader-2/
shader_type canvas_item;
uniform sampler2D screen_texture : hint_screen_texture, repeat_disable, filter_nearest;
uniform float fisheye_strength = 1.0; // Adjust this to control the fisheye effect strength

vec2 fisheye(vec2 uv) {
    vec2 d = uv - 0.5;
    float r = length(d);
    float theta = atan(d.y, d.x);
    float rf = pow(r, fisheye_strength) / pow(0.5, fisheye_strength - 1.0);
    return vec2(0.5) + rf * normalize(d);
}

vec2 curve(vec2 uv)
{
	uv = (uv - 0.5) * 2.0;
	uv *= 1.1;
	uv.x *= 1.0 + pow((abs(uv.y) / 5.0), 2.0);
	uv.y *= 1.0 + pow((abs(uv.x) / 4.0), 2.0);
	uv  = (uv / 2.0) + 0.5;
	uv =  uv *0.92 + 0.04;
	return uv;
}

void fragment() {
    vec2 iResolution = 1.0 / SCREEN_PIXEL_SIZE;
    vec2 q = FRAGCOORD.xy / iResolution.xy;

    // Apply fisheye distortion
    q = fisheye(q);

    vec2 uv = curve(q);
    uv = curve( uv );
    vec3 oricol = texture( screen_texture, vec2(q.x,q.y) ).xyz;
    vec3 col;
	float x =  sin(0.3*TIME+uv.y*21.0)*sin(0.7*TIME+uv.y*29.0)*sin(0.3+0.33*TIME+uv.y*31.0)*0.0017;

    col.r = texture(screen_texture,vec2(x+uv.x+0.001,uv.y+0.001)).x+0.05;
    col.g = texture(screen_texture,vec2(x+uv.x+0.000,uv.y-0.002)).y+0.05;
    col.b = texture(screen_texture,vec2(x+uv.x-0.002,uv.y+0.000)).z+0.05;
    col.r += 0.08*texture(screen_texture,0.75*vec2(x+0.025, -0.027)+vec2(uv.x+0.001,uv.y+0.001)).x;
    col.g += 0.05*texture(screen_texture,0.75*vec2(x+-0.022, -0.02)+vec2(uv.x+0.000,uv.y-0.002)).y;
    col.b += 0.08*texture(screen_texture,0.75*vec2(x+-0.02, -0.018)+vec2(uv.x-0.002,uv.y+0.000)).z;

    col = clamp(col*0.6+0.4*col*col*1.0,0.0,1.0);

    float vig = (0.0 + 1.0*16.0*uv.x*uv.y*(1.0-uv.x)*(1.0-uv.y));
	col *= vec3(pow(vig,0.3));

    col *= vec3(0.95,1.05,0.95);
	col *= 2.8;

	float scans = clamp( 0.35+0.35*sin(3.5*TIME+uv.y*iResolution.y*1.5), 0.0, 1.0);

	float s = pow(scans,1.7);
	col = col*vec3( 0.4+0.7*s) ;

    col *= 1.0+0.01*sin(110.0*TIME);
	if (uv.x < 0.0 || uv.x > 1.0)
		col *= 0.0;
	if (uv.y < 0.0 || uv.y > 1.0)
		col *= 0.0;

	col*=1.0-0.65*vec3(clamp((mod(FRAGCOORD.x, 2.0)-1.0)*2.0,0.0,1.0));

    float comp = smoothstep( 0.1, 0.9, sin(TIME) );


    COLOR = vec4(col,1.0);
}
Tags
CRT, fisheye
The shader code and all code snippets in this post are under CC0 license and can be used freely without the author's permission. Images and videos, and assets depicted in those, do not fall under this license. For more info, see our License terms.

More from thepathgame

SDF Range Rings (3D)

Volumetric Raymarched (animated) Clouds v2

Volumetric Clouds

Related shaders

Fisheye & Anti fisheye Camera Effect

Variable Dot Pattern

Variable Blur – Works with parallax layers

Subscribe
Notify of
guest

1 Comment
Oldest
Newest Most Voted
Inline Feedbacks
View all comments
doradoro
7 months ago

It would be great to be able to reduce the strength to appear better in YouTube videos…