const float PI = 3.14159265;
float map(vec3 p)
{
return length(p) - .4;
}
// aka calc gradient
vec3 calcNormal(vec3 p)
{
return normalize(vec3(
map(p + vec3(.001, .0, .0)) - map(p - vec3(.001, .0, .0)),
map(p + vec3(.0, .001, .0)) - map(p - vec3(.0, .001, .0)),
map(p + vec3(.0, .0, .001)) - map(p - vec3(.0, .0, .001))
));
}
void mainImage( out vec4 fragColor, in vec2 fragCoord )
{
vec2 screen_pos = ((2.0 * fragCoord.xy) - iResolution.xy) / iResolution.y;
float cam_an = iTime;
vec3 cam_orig = vec3(sin(cam_an), .0, cos(cam_an));
vec3 cam_target = vec3(.0, .0, .0);
vec3 cam_forward = normalize(cam_target - cam_orig);
vec3 cam_right = normalize(cross(cam_forward, vec3(.0, 1., .0)));
vec3 cam_up = normalize(cross(cam_right, cam_forward));
vec3 ro = cam_orig;
vec3 rd = normalize(vec3(
screen_pos.x * cam_right +
screen_pos.y * cam_up +
1. * cam_forward
));
vec3 col = vec3(.0);
float t = .0;
for (int step_march = 0; step_march < 100; ++step_march)
{
vec3 p = ro + t * rd;
float h = map(p);
if(h < .001)
{
col = calcNormal(p);
break;
}
t += h;
}
fragColor = vec4(col,1.);
}
const float PI = 3.14159265;
// iquilez
float smin(float a, float b, float k)
{
float h = max(k - abs(a-b), .0) / k;
return min(a, b) - h * h * k * (1./4.);
}
// d1 = sphere, d2 = tube
float map(vec3 p)
{
float d1 = length(p - vec3(3. * cos(iTime), .0, .0)) - .8;
float an = 2. * sin(iTime);
mat2 rot = mat2(
cos(an), -sin(an),
sin(an), cos(an)
);
vec3 q = p;
q.yz = rot * q.yz;
float d2 = length(vec2(q.y, length(q.xz) - 1.)) - .4;
float d = smin(d1, d2, .5);
d += .05 * sin(4. * p.x + 5. * iTime) + .07 * sin(3. * p.y + 5. * iTime);
return d;
}
// aka calc gradient
vec3 calcNormal(vec3 p)
{
vec2 eps = vec2(.001, .0);
return normalize(vec3(
map(p + eps.xyy) - map(p - eps.xyy),
map(p + eps.yxy) - map(p - eps.yxy),
map(p + eps.yyx) - map(p - eps.yyx)
));
}
void mainImage( out vec4 fragColor, in vec2 fragCoord )
{
vec2 screen_pos = ((2.0 * fragCoord.xy) - iResolution.xy) / iResolution.y;
float cam_an = .0; // iTime;
vec3 cam_orig = vec3(5. * sin(cam_an), 4., 5. * cos(cam_an));
vec3 cam_target = vec3(.0, .0, .0);
vec3 cam_forward = normalize(cam_target - cam_orig);
vec3 cam_right = normalize(cross(cam_forward, vec3(.0, 1., .0)));
vec3 cam_up = normalize(cross(cam_right, cam_forward));
vec3 ro = cam_orig;
vec3 rd = normalize(vec3(
screen_pos.x * cam_right +
screen_pos.y * cam_up +
2. * cam_forward
));
vec3 col = vec3(.0);
float t = .0;
for (int step_march = 0; step_march < 100; ++step_march)
{
vec3 p = ro + t * rd;
float h = map(p);
if(h < .001)
{
col = calcNormal(p);
break;
}
t += h;
}
fragColor = vec4(col,1.);
}
참고 자료 : https://www.udemy.com/
온라인 강의 - 자신의 일정에 맞춰 뭐든지 배워 보세요 | Udemy
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