//#define ANOTHER_LEVEL
/* SHADERTOY FROM HERE */
float guiLead = 0.6;
float guiInnerRatio = 0.4407892623709694;
float guiFocal = 3.;
float guiRotateModel = 0.4560833039600971;
float guiDebug = 0.6749066960348409;
float guiZipOffset = 30.;
float guiZipSize = 60.;
float guiZipSpeed = 3.3;
float guiZoom = 0.1;
float guiModelScale = 7.749066960348409;
mat4 cameraMatrix = mat4(
-0.7063226699829102,
0.7052236199378967,
0.06198469549417496,
0,
-0.30620118975639343,
-0.3832840919494629,
0.8714323043823242,
0,
0.6382971405982971,
0.5965006947517395,
0.48660656809806824,
0,
0.14653973281383514,
0.6211488246917725,
0.13233166933059692,
1
);
vec3 camPosition = vec3(0.14653973281383514, 0.6211488246917725, 0.13233166933059692);
#define PI 3.14159265359
#define HALF_PI 1.5707963267948966
#define TAU 6.28318530718
#define PHI 1.618033988749895
// --------------------------------------------------------
// Utils
// --------------------------------------------------------
#define saturate(x) clamp(x, 0., 1.)
// Rotate around a coordinate axis (i.e. in a plane perpendicular to that axis) by angle <a>.
// Read like this: R(p.xz, a) rotates "x towards z".
// This is fast if <a> is a compile-time constant and slower (but still practical) if not.
void pR(inout vec2 p, float a) {
p
= cos(a
)*p
+ sin(a
)*vec2
(p.
y, -p.
x);}
// http://www.neilmendoza.com/glsl-rotation-about-an-arbitrary-axis/
mat3 rotationMatrix(vec3 axis, float angle)
{
axis = normalize(axis);
float oc = 1.0 - c;
return mat3(
oc * axis.x * axis.x + c, oc * axis.x * axis.y - axis.z * s, oc * axis.z * axis.x + axis.y * s,
oc * axis.x * axis.y + axis.z * s, oc * axis.y * axis.y + c, oc * axis.y * axis.z - axis.x * s,
oc * axis.z * axis.x - axis.y * s, oc * axis.y * axis.z + axis.x * s, oc * axis.z * axis.z + c
);
}
float range(float vmin, float vmax, float value) {
return (value - vmin) / (vmax - vmin);
}
float rangec(float a, float b, float t) {
return clamp(range(a, b, t), 0., 1.);
}
float vmax(vec2 v) {
return max(v.x, v.y);
}
float fBox2(vec2 p, vec2 b) {
return length(max(d, vec2(0))) + vmax(min(d, vec2(0)));
}
// Repeat space along one axis. Use like this to repeat along the x axis:
// <float cell = pMod1(p.x,5);> - using the return value is optional.
float pMod1(inout float p, float size) {
float halfsize = size*0.5;
float c
= floor((p
+ halfsize
)/size
); p = mod(p + halfsize, size) - halfsize;
return c;
}
vec3 cartToPolar(vec3 p) {
float x = p.x; // distance from the plane it lies on
float a
= atan(p.
y, p.
z); // angle around center float r = length(p.zy); // distance from center
return vec3(x, a, r);
}
vec3 polarToCart(vec3 p) {
return vec3(
p.x,
);
}
vec2 closestPointOnLine(vec2 line, vec2 point){
line = normalize(line);
float d = dot(point, line);
return line * d;
}
// Closest of two points
vec3 closestPoint(vec3 pos, vec3 p1, vec3 p2) {
if (length(pos - p1) < length(pos - p2)) {
return p1;
} else {
return p2;
}
}
// --------------------------------------------------------
// Helix
// --------------------------------------------------------
// Closest point on a helix for one revolution
vec3 closestHelixSection(vec3 p, float lead, float radius) {
p = cartToPolar(p);
p.y *= radius;
vec2 line = vec2(lead, radius * PI * 2.);
vec2 closest = closestPointOnLine(line, p.xy);
closest.y /= radius;
vec3 closestCart = polarToCart(vec3(closest, radius));
return closestCart;
}
// Closest point on a helix for infinite revolutions
vec3 closestHelix(vec3 p, float lead, float radius) {
float c = pMod1(p.x, lead);
vec3 offset = vec3(lead, 0, 0);
vec3 A = closestHelixSection(p, lead, radius);
vec3 B = closestHelixSection(p + offset, lead, radius) - offset;
vec3 C = closestHelixSection(p - offset, lead, radius) + offset;
vec3 closest = closestPoint(p, A, closestPoint(p, B, C));
closest += offset * c;
return closest;
}
// Cartesian to helix coordinates
void pModHelix(inout vec3 p, float lead, float radius) {
vec3 closest = closestHelix(p, lead, radius);
float helixAngle
= atan((2.
* PI
* radius
) / lead
); vec3 normal = normalize(closest - vec3(closest.x,0,0));
vec3 tangent = vec3(1,0,0) * rotationMatrix(normal, helixAngle);
float x = (closest.x / lead) * radius * PI * 2.;
float y = dot(p - closest, cross(tangent, normal));
float z = dot(p - closest, normal);
p = vec3(x, y, z);
}
float pModHelixScale(inout vec3 p, float lead, float innerRatio) {
float radius = mix(.25, .5, innerRatio);
pModHelix(p, lead, radius);
float scale = mix(.5, 0., innerRatio);
p /= scale;
return 1. / scale;
}
float pModHelixUnwrap(inout vec3 p, float lead, float innerRatio, float t) {
float radius = mix(.25, .5, innerRatio);
float adjust = (1. / width);
float offset = ((.5 * adjust) - .5) * 7.;
vec3 pp = p;
pp.z -= radius;
pR(pp.xy, PI * -.5);
pp.x *= -1.;
p.z += offset;
radius += offset;
pModHelix(p, lead, radius);
p = mix(p, pp, rangec(.8, 1., t));
float scale = mix(.5, 0., innerRatio);
p /= scale;
return 1. / scale;
}
// --------------------------------------------------------
// Modelling
// --------------------------------------------------------
struct Model {
float dist;
vec3 albedo;
int id;
};
float anim(float t, float index) {
float overlap = .5;
float steps = 2.;
float all = mix(steps, 1., overlap);
float width = 1. / (all - 1.);
float each = width * (1.- overlap);
float start = index * each - width * .5;
float end = start + width;
return range(start, end, t);
}
float unzip(vec3 p, float t) {
float size = guiZipSize;
float speed = guiZipSpeed;
t *= size * speed;
if (sign(p.y) != sign(p.x)) {
float radius = mix(.25, .5, guiInnerRatio);
float scale = mix(.5, 0., guiInnerRatio);
float factor = radius / scale * PI * 2.;
t -= (factor - .5);
}
return range
(size
, 0.
, abs(p.
x) + size
- t
); }
void addPipe(inout float d, vec3 p, float scale, float tt) {
float t = clamp(tt, 0., 1.);
float boundry = 1.;
float part;
float separate = (
rangec(0., boundry * .01, t) * .3 +
rangec(boundry * .01, boundry, t) * .7
);
float round = rangec(.0, 1., t);
part = fBox2(p.yz, vec2(mix(guiLead * 2., .5, separate), .5));
part = mix(part, length(p.yz) - .5, round);
part /= scale;
d = mix(d, part, smoothstep(.0, .01, t));
}
void unzipHelixModel(inout float d, inout float scale, inout vec3 p, float lead, float innerRatio, float step, float invert) {
float offset = guiZipOffset / lead;
scale *= pModHelixScale(p, lead, innerRatio);
p.x *= -1.;
float t1
= unzip
(p
+ vec3
(offset
,0,0) * invert
, anim
(time, step
)); addPipe(d, p, scale, t1);
}
Model map(vec3 p) {
float part, d, t1, t2, t3, t4;
float lead = guiLead;
float innerRatio = guiInnerRatio;
vec2 uv1, uv2, uv3;
p /= guiModelScale;
vec3 pp = p;
d = 1e12;
float s = mix(.5, 0., innerRatio);
pR
(p.
xy, PI
* -.5 * time + guiRotateModel
* PI
* 2.
);
p *= scale;
p.z += .5;
scale
*= pModHelixUnwrap
(p
, lead
, innerRatio
, time); p.x *= -1.;
scale *= pModHelixScale(p, lead, innerRatio);
p.x *= -1.;
#ifdef ANOTHER_LEVEL
scale *= pModHelixScale(p, lead, innerRatio);
p.x *= -1.;
#endif
d = min(d, length(p.yz) - .5);
d /= scale;
unzipHelixModel(d, scale, p, lead, innerRatio, -1., 1.);
unzipHelixModel(d, scale, p, lead, innerRatio, 0., -1.);
unzipHelixModel(d, scale, p, lead, innerRatio, 1., 1.);
d *= guiModelScale;
return Model(d, vec3(0), 1);
}
// --------------------------------------------------------
// Ray Marching
// Adapted from: https://www.shadertoy.com/view/Xl2XWt
// --------------------------------------------------------
const float MAX_TRACE_DISTANCE = 1.5; // max trace distance
const float INTERSECTION_PRECISION = .001; // precision of the intersection
const int NUM_OF_TRACE_STEPS = 100;
const float FUDGE_FACTOR = 1.; // Default is 1, reduce to fix overshoots
struct CastRay {
vec3 origin;
vec3 direction;
};
struct Ray {
vec3 origin;
vec3 direction;
float len;
};
struct Hit {
Ray ray;
Model model;
vec3 pos;
bool isBackground;
vec3 normal;
bool isOutline;
};
// Faster runtime
vec3 _calcNormal(vec3 pos){
vec3 eps = vec3(.0001,0,0);
vec3 nor = vec3(
map(pos+eps.xyy).dist - map(pos-eps.xyy).dist,
map(pos+eps.yxy).dist - map(pos-eps.yxy).dist,
map(pos+eps.yyx).dist - map(pos-eps.yyx).dist );
return normalize(nor);
}
// Faster compilation
const int NORMAL_STEPS = 6;
vec3 calcNormal(vec3 pos){
vec3 eps = vec3(.001,0,0);
vec3 nor = vec3(0);
float invert = 1.;
for (int i = 0; i < NORMAL_STEPS; i++){
nor += map(pos + eps * invert).dist * eps * invert;
eps = eps.zxy;
invert *= -1.;
}
return normalize(nor);
}
Hit raymarch(CastRay castRay){
float currentDist = INTERSECTION_PRECISION * 2.0;
float outlineDist = INTERSECTION_PRECISION * 2.0;
Model model;
float outline = .0023;
bool isOutline = false;
bool miss = false;
float lastDist = currentDist;
Ray ray = Ray(castRay.origin, castRay.direction, 0.);
for( int i=0; i< NUM_OF_TRACE_STEPS ; i++ ){
if (currentDist < INTERSECTION_PRECISION || ray.len > MAX_TRACE_DISTANCE) {
break;
}
model = map(ray.origin + ray.direction * ray.len);
lastDist = currentDist;
currentDist = model.dist;
miss = currentDist > lastDist;
outlineDist = currentDist * -1. + outline;
isOutline = outlineDist > .0 && outlineDist < currentDist && miss;
if (isOutline) {
currentDist = outlineDist;
}
ray.len += currentDist * FUDGE_FACTOR;
}
bool isBackground = false;
vec3 pos = vec3(0);
vec3 normal = vec3(0);
if (ray.len > MAX_TRACE_DISTANCE) {
isBackground = true;
} else {
pos = ray.origin + ray.direction * ray.len;
normal = calcNormal(pos);
}
return Hit(ray, model, pos, isBackground, normal, isOutline);
}
// --------------------------------------------------------
// Rendering
// --------------------------------------------------------
float softshadow( in vec3 ro, in vec3 rd, in float mint, in float tmax )
{
float res = 1.0;
float t = mint;
float ph = 1e10;
for( int i=0; i<32; i++ )
{
float h = map( ro + rd*t ).dist;
res = min( res, 10.0*h/t );
t += h;
if( res<0.0001 || t>tmax ) break;
}
return clamp( res, 0.0, 1.0 );
}
float calcAO( in vec3 pos, in vec3 nor )
{
float occ = 0.0;
float sca = 1.0;
for( int i=0; i<5; i++ )
{
float hr = 0.01 + 0.12*float(i)/4.0;
vec3 aopos = nor * hr + pos;
float dd = map( aopos ).dist;
occ += -(dd-hr)*sca;
sca *= 0.95;
}
return clamp( 1.0 - 3.0*occ, 0.0, 1.0 );
}
vec3 doLighting(vec3 pos, vec3 nor, vec3 ref, vec3 rd) {
vec3 col;
vec3 up = normalize(vec3(1));
// lighitng
float occ = mix(calcAO( pos, nor ), 1., .8);
vec3 lig = normalize(vec3(0,.2,1));
float amb = clamp(dot(nor, up) * .5 + .5, 0., 1.);
float dif = clamp( dot( nor, lig ), 0.0, 1.0 );
float fre
= pow( clamp
(1.0+dot
(nor
,rd
),0.0,1.0), 2.0 ); vec3 hal = normalize( lig-rd );
float spe
= pow(clamp
( dot
( nor
, hal
), 0.0, 1.0 ),16.0);
vec3 cA = vec3(.7,.3,.9);
vec3 cB = vec3(.4,.9,.8);
vec3 cC = vec3(.7,0,.7);
col = mix(cA, cB, rangec(.0, 1., dot(-rd, nor))); // need better ramp
col = mix(col, vec3(.8,.5,1), rangec(.5, 1., dif) * .5);
col += cC * rangec(.5, 1., dif) * .1;
dif *= softshadow( pos, lig, 0.02, 2.5 ) * .9;
vec3 lin = vec3(0);
lin += .5 * dif;
lin += .1 * spe * dif;
lin += .2 * fre * occ;
lin += .5 * amb * occ;
lin += .4 * occ;
col = col*lin;
return col;
}
void render(inout vec3 color, Hit hit){
vec3 background = vec3(.1)* vec3(.5,0,1);
background = color;
if (hit.isBackground) {
color = background;
return;
}
if (hit.isOutline) {
color = vec3(background * .33);
} else {
vec3 ref = reflect(hit.ray.direction, hit.normal);
color = doLighting(
hit.pos,
hit.normal,
ref,
hit.ray.direction
);
}
float fog = length(camPosition - hit.pos);
fog = smoothstep(float(MAX_TRACE_DISTANCE) * .36, float(MAX_TRACE_DISTANCE), fog);
color = mix(color, background, fog);
}
void mainImage( out vec4 fragColor, in vec2 fragCoord )
{
vec2 p = (-iResolution.xy + 2.0*fragCoord.xy)/iResolution.y;
vec3 color = mix(vec3(.4,.3,.5) * .9, vec3(.6), -.2);
vec3 bgA = vec3(.6,.5,.8) * .55;
vec3 bgB = vec3(.7,.9,1.) * .5;
color = mix(bgA, bgB, dot(p, normalize(vec2(.2,-.6))) * .5);
float camDist = length(camPosition);
mat4 camMat = cameraMatrix;
float focalLength = guiFocal;
vec3 rd = normalize(
(vec4(p, -focalLength, 1) * camMat).xyz
);
Hit hit = raymarch(CastRay(camPosition, rd));
render(color, hit);
vec2 uv = fragCoord/iResolution.xy;
16. * uv.x * uv.y * (1. - uv.x) * (1. - uv.y),
0.075
);
color *= vec3(.9, .95, 1.) * vig * 1.1;
color
= mix
(color
, vec3
(pow(length
(color
* .6), 2.
)), .1); color *= 1.05;
color
= pow(color
, vec3
(1.2,1.3,1.2));
fragColor = vec4(color,1.0);
}
