mirror of
https://github.com/Ttanasart-pt/Pixel-Composer.git
synced 2024-11-14 22:43:53 +01:00
239 lines
6.3 KiB
GLSL
239 lines
6.3 KiB
GLSL
//Inigo Quilez
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//Oh where would I be without you.
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varying vec2 v_vTexcoord;
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varying vec4 v_vColour;
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const int MAX_MARCHING_STEPS = 512;
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const float EPSILON = 1e-6;
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const float PI = 3.14159265358979323846;
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uniform vec3 position;
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uniform vec3 rotation;
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uniform float objectScale;
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uniform float fov;
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uniform vec2 viewRange;
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uniform float density;
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uniform int iteration;
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uniform float threshold;
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uniform int adaptiveIteration;
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uniform float detailScale;
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uniform float detailAtten;
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mat3 rotMatrix, irotMatrix;
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vec3 eye, dir;
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#region ////========== Transform ============
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mat3 rotateX(float dg) {
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float c = cos(radians(dg));
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float s = sin(radians(dg));
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return mat3(
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vec3(1, 0, 0),
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vec3(0, c, -s),
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vec3(0, s, c)
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);
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}
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mat3 rotateY(float dg) {
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float c = cos(radians(dg));
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float s = sin(radians(dg));
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return mat3(
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vec3( c, 0, s),
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vec3( 0, 1, 0),
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vec3(-s, 0, c)
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);
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}
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mat3 rotateZ(float dg) {
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float c = cos(radians(dg));
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float s = sin(radians(dg));
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return mat3(
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vec3(c, -s, 0),
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vec3(s, c, 0),
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vec3(0, 0, 1)
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);
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}
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mat3 inverse(mat3 m) {
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float a00 = m[0][0], a01 = m[0][1], a02 = m[0][2];
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float a10 = m[1][0], a11 = m[1][1], a12 = m[1][2];
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float a20 = m[2][0], a21 = m[2][1], a22 = m[2][2];
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float b01 = a22 * a11 - a12 * a21;
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float b11 = -a22 * a10 + a12 * a20;
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float b21 = a21 * a10 - a11 * a20;
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float det = a00 * b01 + a01 * b11 + a02 * b21;
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return mat3(b01, (-a22 * a01 + a02 * a21), (a12 * a01 - a02 * a11),
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b11, (a22 * a00 - a02 * a20), (-a12 * a00 + a02 * a10),
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b21, (-a21 * a00 + a01 * a20), (a11 * a00 - a01 * a10)) / det;
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}
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#endregion
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#region ////============= Noise ==============
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vec3 mod289(vec3 x) { return x - floor(x * (1.0 / 289.0)) * 289.0; }
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vec4 mod289(vec4 x) { return x - floor(x * (1.0 / 289.0)) * 289.0; }
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vec4 permute(vec4 x) { return mod289(((x * 34.0) + 10.0) * x); }
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vec4 taylorInvSqrt(vec4 r) { return 1.79284291400159 - 0.85373472095314 * r; }
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float snoise(vec3 vec) {
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vec3 v = vec * 4.;
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const vec2 C = vec2(1.0 / 6.0, 1.0 / 3.0);
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const vec4 D = vec4(0.0, 0.5, 1.0, 2.0);
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// First corner
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vec3 i = floor(v + dot(v, C.yyy));
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vec3 x0 = v - i + dot(i, C.xxx);
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// Other corners
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vec3 g = step(x0.yzx, x0.xyz);
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vec3 l = 1.0 - g;
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vec3 i1 = min( g.xyz, l.zxy );
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vec3 i2 = max( g.xyz, l.zxy );
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// x0 = x0 - 0.0 + 0.0 * C.xxx;
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// x1 = x0 - i1 + 1.0 * C.xxx;
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// x2 = x0 - i2 + 2.0 * C.xxx;
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// x3 = x0 - 1.0 + 3.0 * C.xxx;
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vec3 x1 = x0 - i1 + C.xxx;
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vec3 x2 = x0 - i2 + C.yyy; // 2.0*C.x = 1/3 = C.y
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vec3 x3 = x0 - D.yyy; // -1.0+3.0*C.x = -0.5 = -D.y
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// Permutations
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i = mod289(i);
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vec4 p = permute( permute( permute(
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i.z + vec4(0.0, i1.z, i2.z, 1.0 ))
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+ i.y + vec4(0.0, i1.y, i2.y, 1.0 ))
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+ i.x + vec4(0.0, i1.x, i2.x, 1.0 ));
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// Gradients: 7x7 points over a square, mapped onto an octahedron.
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// The ring size 17*17 = 289 is close to a multiple of 49 (49*6 = 294)
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float n_ = 0.142857142857; // 1.0/7.0
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vec3 ns = n_ * D.wyz - D.xzx;
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vec4 j = p - 49.0 * floor(p * ns.z * ns.z); // mod(p,7*7)
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vec4 x_ = floor(j * ns.z);
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vec4 y_ = floor(j - 7.0 * x_ ); // mod(j,N)
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vec4 x = x_ * ns.x + ns.yyyy;
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vec4 y = y_ * ns.x + ns.yyyy;
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vec4 h = 1.0 - abs(x) - abs(y);
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vec4 b0 = vec4( x.xy, y.xy );
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vec4 b1 = vec4( x.zw, y.zw );
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//vec4 s0 = vec4(lessThan(b0,0.0))*2.0 - 1.0;
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//vec4 s1 = vec4(lessThan(b1,0.0))*2.0 - 1.0;
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vec4 s0 = floor(b0) * 2.0 + 1.0;
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vec4 s1 = floor(b1) * 2.0 + 1.0;
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vec4 sh = -step(h, vec4(0.0));
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vec4 a0 = b0.xzyw + s0.xzyw * sh.xxyy ;
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vec4 a1 = b1.xzyw + s1.xzyw * sh.zzww ;
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vec3 p0 = vec3(a0.xy, h.x);
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vec3 p1 = vec3(a0.zw, h.y);
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vec3 p2 = vec3(a1.xy, h.z);
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vec3 p3 = vec3(a1.zw, h.w);
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//Normalise gradients
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vec4 norm = taylorInvSqrt(vec4(dot(p0, p0), dot(p1, p1), dot(p2, p2), dot(p3, p3)));
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p0 *= norm.x;
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p1 *= norm.y;
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p2 *= norm.z;
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p3 *= norm.w;
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// Mix final noise value
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vec4 m = max(0.5 - vec4(dot(x0, x0), dot(x1, x1), dot(x2, x2), dot(x3, x3)), 0.0);
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m = m * m;
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float n = 105.0 * dot( m * m, vec4( dot(p0, x0), dot(p1, x1), dot(p2, x2), dot(p3, x3) ) );
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n = mix(0.0, 0.5 + 0.5 * n, smoothstep(0.0, 0.003, vec.z));
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return n;
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}
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float simplex(in vec3 pos, in int itr) {
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vec3 xyz = vec3(pos);
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xyz.z = abs(xyz.z);
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float amp = 1.;
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float n = 0.;
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float acc = 0.;
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for(int i = 0; i < itr; i++) {
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n += snoise(xyz) * amp;
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acc += amp;
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amp *= detailAtten;
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xyz *= detailScale;
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}
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return n / acc;
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}
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#endregion
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float volume(vec3 pos, float ratio) {
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int it = adaptiveIteration == 1? int(max(1., ratio * float(iteration))) : iteration;
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float ss = simplex(pos * 0.5, it / 2);
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float sp = simplex(pos, it);
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float thr = threshold;
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float d1 = clamp(max(0., ss - thr) / (1. - thr), 0., 1.);
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d1 = smoothstep(.2, .8, d1);
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d1 *= clamp(1. - distance(pos, eye) / 16., 0., 1.);
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float ds = clamp(max(0., sp - thr) / (1. - thr), 0., 1.);
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ds *= d1;
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return ds;
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}
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float marchDensity(vec3 camera, vec3 direction) {
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float maxx = float(MAX_MARCHING_STEPS);
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float st = 1. / maxx;
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float _densi = 0.;
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float dens = pow(2., 10. * density - 10.);
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for (float i = 0.; i <= maxx; i++) {
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float depth = mix(viewRange.x, viewRange.y, i * st);
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vec3 pos = camera + depth * direction;
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float mden = volume(pos, 1. - i * st);
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_densi += dens * mden;
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}
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return _densi;
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}
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void main() {
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mat3 rx = rotateX(rotation.x);
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mat3 ry = rotateY(rotation.y);
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mat3 rz = rotateZ(rotation.z);
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rotMatrix = rx * ry * rz;
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irotMatrix = inverse(rotMatrix);
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float z = 1. / tan(radians(fov) / 2.);
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dir = normalize(vec3((v_vTexcoord - .5) * 2., -z));
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eye = vec3(0., 0., 5.);
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// vec2 cps = (v_vTexcoord - .5) * 2.;
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// dir = vec3(0., 0., -1.);
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// eye = vec3(cps, 5.);
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dir = normalize(irotMatrix * dir) / objectScale;
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eye = irotMatrix * eye;
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eye /= objectScale;
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eye -= position;
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float dens = marchDensity(eye, dir);
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gl_FragColor = vec4(vec3(dens), 1.);
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} |