VHS Post Processing
VHS shader for analog horror games.
It contains plenty of options to control the scanlines, vignette, and image distortions.
Developed for the indie analog horror game Room2Room.
Instructions
- Create a CanvasLayer
- Add a ColorRect and sets its anchors to Full Rect
- Add a ShaderMaterial and the shader to the ColorRect
- Add an RGBA noise texture such as this one
Shader code
// https://www.shadertoy.com/view/MdffD7
// Fork of FMS_Cat's VCR distortion shader
shader_type canvas_item;
// TODO: Add uniforms for tape crease discoloration and image jiggle
uniform sampler2D screen_texture: hint_screen_texture, filter_linear_mipmap, repeat_disable;
uniform vec2 vhs_resolution = vec2(320.0, 240.0);
uniform int samples = 2;
uniform float crease_noise: hint_range(0.0, 2.0, 0.1) = 1.0;
uniform float crease_opacity: hint_range(0.0, 1.0, 0.1) = 0.5;
uniform float filter_intensity: hint_range(0.0, 1.0, 0.1) = 0.1;
group_uniforms tape_crease;
uniform float tape_crease_smear: hint_range(0.0, 2.0, 0.1) = 0.2;
uniform float tape_crease_intensity: hint_range(0.0, 1.0, 0.1) = 0.2;
uniform float tape_crease_jitter: hint_range(0.0, 1.0, 0.01) = 0.10;
uniform float tape_crease_speed: hint_range(-2.0, 2.0, 0.1) = 0.5;
uniform float tape_crease_discoloration: hint_range(0.0, 2.0, 0.1) = 1.0;
group_uniforms bottom_border;
uniform float bottom_border_thickness: hint_range(0.0,32.0, 0.1) = 6.0;
uniform float bottom_border_jitter: hint_range(0.0, 24.0, 0.5) = 6.0;
group_uniforms noise;
uniform float noise_intensity: hint_range(0.0, 1.0, 0.1) = 0.1;
uniform sampler2D noise_texture: filter_linear_mipmap, repeat_enable;
float v2random(vec2 uv) {
return texture(noise_texture, mod(uv, vec2(1.0))).x;
}
mat2 rotate2D(float t) {
return mat2(vec2(cos(t), sin(t)), vec2(-sin(t), cos(t)));
}
vec3 rgb2yiq(vec3 rgb) {
return mat3(vec3(0.299, 0.596, 0.211), vec3(0.587, -0.274, -0.523), vec3(0.114, -0.322, 0.312)) * rgb;
}
vec3 yiq2rgb(vec3 yiq) {
return mat3(vec3(1.0, 1.0, 1.0), vec3(0.956, -0.272, -1.106), vec3(0.621, -0.647, 1.703)) * yiq;
}
vec3 vhx_tex_2D(sampler2D tex, vec2 uv, float rot) {
vec3 yiq = vec3(0.0);
for (int i = 0; i < samples; i++) {
yiq += rgb2yiq(texture(tex, uv - vec2(float(i), 0.0) / vhs_resolution).xyz) *
vec2(float(i), float(samples - 1 - i)).yxx / float(samples - 1)
/ float(samples) * 2.0;
}
if (rot != 0.0) {
yiq.yz *= rotate2D(rot * tape_crease_discoloration);
}
return yiq2rgb(yiq);
}
void fragment() {
vec2 uvn = UV;
vec3 col = vec3(0.0, 0.0, 0.0);
// Tape wave.
uvn.x += (v2random(vec2(uvn.y / 10.0, TIME / 10.0) / 1.0) - 0.5) / vhs_resolution.x * 1.0;
uvn.x += (v2random(vec2(uvn.y, TIME * 10.0)) - 0.5) / vhs_resolution.x * 1.0;
// tape crease
float tc_phase = smoothstep(0.9, 0.96, sin(uvn.y * 8.0 - (TIME * tape_crease_speed + tape_crease_jitter * v2random(TIME * vec2(0.67, 0.59))) * PI * 1.2));
float tc_noise = smoothstep(0.3, 1.0, v2random(vec2(uvn.y * 4.77, TIME)));
float tc = tc_phase * tc_noise;
uvn.x = uvn.x - tc / vhs_resolution.x * 8.0 * tape_crease_smear;
// switching noise
float sn_phase = smoothstep(1.0 - bottom_border_thickness / vhs_resolution.y, 1.0, uvn.y);
uvn.x += sn_phase * (v2random(vec2(UV.y * 100.0, TIME * 10.0)) - 0.5) / vhs_resolution.x * bottom_border_jitter;
// fetch
col = vhx_tex_2D(screen_texture, uvn, tc_phase * 0.2 + sn_phase * 2.0);
// crease noise
float cn = tc_noise * crease_noise * (0.7 * tc_phase * tape_crease_intensity + 0.3);
if (0.29 < cn) {
vec2 V = vec2(0.0, crease_opacity);
vec2 uvt = (uvn + V.yx * v2random(vec2(uvn.y, TIME))) * vec2(0.1, 1.0);
float n0 = v2random(uvt);
float n1 = v2random(uvt + V.yx / vhs_resolution.x);
if (n1 < n0) {
col = mix(col, 2.0 * V.yyy, pow(n0, 10.0));
}
}
// ac beat
col *= 1.0 + 0.1 * smoothstep(0.4, 0.6, v2random(vec2(0.0, 0.1 * (UV.y + TIME * 0.2)) / 10.0));
// color noise
col *= 1.0 - noise_intensity * 0.5 + noise_intensity * texture(noise_texture, mod(uvn * vec2(1.0, 1.0) + TIME * vec2(5.97, 4.45), vec2(1.0))).xyz;
col = clamp(col, 0.0, 1.0);
// yiq
col = rgb2yiq(col);
col = vec3(0.9, 1.1, 1.5) * col + vec3(0.1, -0.1, 0.0) * filter_intensity;
col = yiq2rgb(col);
COLOR = vec4(col, 1.0);
}
hot
very nice! works well for the aesthetic I’m going for in my game
Very nice! What’s your game?
nice but buttons dont wrok with it
Oh I’m sorry to hear that, it’s likely due to the ColorRect’s mouse_filter property set to stop. Try setting it to pass or ignore, instead.
edit: nvm i found it lol
this is perfect for indie games… this give the final touch for games that looks “too clean”
perfect! I need exactly the one you have right now, how do I achieve this?![comment image](https://godotshaders.com/wp-content/uploads/2021/01/backrooms.gif)