armory/raw/pt_trace_pass/pt_trace_pass.frag.glsl
2016-10-12 17:52:27 +02:00

198 lines
6 KiB
GLSL

#version 450
#ifdef GL_ES
precision mediump float;
#endif
in vec3 initialRay;
in vec2 texCoord;
out vec4 fragColor;
uniform vec3 eye;
//uniform float textureWeight;
uniform float timeSinceStart;
//uniform sampler2D stexture;
uniform float glossiness;
//vec3 roomCubeMin = vec3(0.0, 0.0, 0.0);
//vec3 roomCubeMax = vec3(1.0, 1.0, 1.0);
vec3 origin;
vec3 ray;
vec3 colorMask = vec3(1.0);
vec3 accumulatedColor = vec3(0.0);
uniform vec3 light;
uniform vec3 cubeCenter0;
uniform vec3 cubeSize0;
uniform vec3 cubeColor0;
vec2 intersectCube(vec3 origin, vec3 ray, vec3 cubeCenter, vec3 cubeSize) {
vec3 cubeMin = cubeCenter - cubeSize;
vec3 cubeMax = cubeCenter + cubeSize;
vec3 tMin = (cubeMin - origin) / ray;
vec3 tMax = (cubeMax - origin) / ray;
vec3 t1 = min(tMin, tMax);
vec3 t2 = max(tMin, tMax);
float tNear = max(max(t1.x, t1.y), t1.z);
float tFar = min(min(t2.x, t2.y), t2.z);
return vec2(tNear, tFar);
}
vec3 normalForCube(vec3 hit, vec3 cubeCenter, vec3 cubeSize) {
vec3 cubeMin = cubeCenter - cubeSize;
vec3 cubeMax = cubeCenter + cubeSize;
if (hit.x < cubeMin.x + 0.0001) return vec3(-1.0, 0.0, 0.0);
else if (hit.x > cubeMax.x - 0.0001) return vec3(1.0, 0.0, 0.0);
else if (hit.y < cubeMin.y + 0.0001) return vec3(0.0, -1.0, 0.0);
else if (hit.y > cubeMax.y - 0.0001) return vec3(0.0, 1.0, 0.0);
else if (hit.z < cubeMin.z + 0.0001) return vec3(0.0, 0.0, -1.0);
//else return vec3(0.0, 0.0, 1.0);
return vec3(0.0, 0.0, 1.0);
}
float intersectSphere(vec3 origin, vec3 ray, vec3 sphereCenter, float sphereRadius) {
vec3 toSphere = origin - sphereCenter;
float a = dot(ray, ray);
float b = 2.0 * dot(toSphere, ray);
float c = dot(toSphere, toSphere) - sphereRadius*sphereRadius;
float discriminant = b*b - 4.0*a*c;
if (discriminant > 0.0) {
float t = (-b - sqrt(discriminant)) / (2.0 * a);
if (t > 0.0) return t;
}
return 10000.0;
}
vec3 normalForSphere(vec3 hit, vec3 sphereCenter, float sphereRadius) {
return (hit - sphereCenter) / sphereRadius;
}
float random(vec3 scale, float seed) {
// return fract(sin(dot(texCoord.xyx + seed, scale)) * 43758.5453 + seed);
float d = 43758.5453;
float dt = dot(texCoord.xyx + seed,scale);
float sn = mod(dt,3.1415926);
return fract(sin(sn) * d);
}
vec3 cosineWeightedDirection(float seed, vec3 normal) {
float u = random(vec3(12.9898, 78.233, 151.7182), seed);
float v = random(vec3(63.7264, 10.873, 623.6736), seed);
float r = sqrt(u);
float angle = 6.283185307179586 * v;
// compute basis from normal
vec3 sdir, tdir;
if (abs(normal.x) < 0.5) {
sdir = cross(normal, vec3(1.0, 0.0, 0.0));
}
else {
sdir = cross(normal, vec3(0.0, 1.0, 0.0));
}
tdir = cross(normal, sdir);
return r*cos(angle)*sdir + r*sin(angle)*tdir + sqrt(1.0-u)*normal;
}
vec3 uniformlyRandomDirection(float seed) {
float u = random(vec3(12.9898, 78.233, 151.7182), seed);
float v = random(vec3(63.7264, 10.873, 623.6736), seed);
float z = 1.0 - 2.0 * u;
float r = sqrt(1.0 - z * z);
float angle = 6.283185307179586 * v;
return vec3(r * cos(angle), r * sin(angle), z);
}
vec3 uniformlyRandomVector(float seed) {
return uniformlyRandomDirection(seed) * sqrt(random(vec3(36.7539, 50.3658, 306.2759), seed));
}
float shadow(vec3 origin, vec3 ray) {
vec2 tCube0 = intersectCube(origin, ray, cubeCenter0, cubeSize0);
if (tCube0.x > 0.0 && tCube0.x < 1.0 && tCube0.x < tCube0.y) return 0.0;
return 1.0;
}
int doBounce(float time, vec3 light, int bounce) {
// compute the intersection with everything
vec2 tCube0 = intersectCube(origin, ray, cubeCenter0, cubeSize0);
// find the closest intersection
float t = 10000.0;
if (tCube0.x > 0.0 && tCube0.x < tCube0.y && tCube0.x < t) t = tCube0.x;
// info about hit
vec3 hit = origin + ray * t;
vec3 surfaceColor = vec3(0.75);
float specularHighlight = 0.0;
vec3 normal;
if (t == 10000.0) {
//break;
return 0;
}
else {
int aa = 0;
if (aa == 1) {aa = 0;} // hack to discard the first 'else' in 'else if'
// have to compare intersectStr.x < intersectStr.y otherwise two coplanar
// cubes will look wrong (one cube will "steal" the hit from the other)
else if (t == tCube0.x) { if (tCube0.x < tCube0.y) normal = normalForCube(hit, cubeCenter0, cubeSize0); surfaceColor = cubeColor0; }
ray = cosineWeightedDirection(time + float(bounce), normal);
}
// compute diffuse lighting contribution
vec3 toLight = light - hit;
//float diffuse = max(0.0, dot(normalize(toLight), normal));
float diffuse = max(0.0, dot(normalize(toLight), normal)) / dot(toLight,toLight);
// do light bounce
colorMask *= surfaceColor;
//if (bounce > 0) {
// trace a shadow ray to the light
float shadowIntensity = shadow(hit + normal * 0.0001, toLight);
accumulatedColor += colorMask * (0.5 * diffuse * shadowIntensity);
accumulatedColor += colorMask * specularHighlight * shadowIntensity;
//}
// calculate next origin
origin = hit;
return 0;
}
vec3 calculateColor(float time, vec3 _origin, vec3 _ray, vec3 light) {
//vec3 colorMask = vec3(1.0);
//vec3 accumulatedColor = vec3(0.0);
origin = _origin;
ray = _ray;
// main raytracing loop
//for (int bounce = 0; bounce < 2; bounce++) {
int a;
a = doBounce(time, light, 0);
a = doBounce(time, light, 1);
a = doBounce(time, light, 2);
//}
return accumulatedColor;
}
void main() {
float time = 0.0;//timeSinceStart;
//timeSinceStart % 46735.275 ) / 1000;
vec3 col = vec3(0.0);
const int samples = 1;
vec3 newLight;
//for (int i = 0; i < samples; i++) {
newLight = light + uniformlyRandomVector(time - 53.0) * 0.1;
col += calculateColor(time, eye, initialRay, newLight);
time += 0.35;
//}
fragColor = vec4(vec3(col / samples), 1.0);
fragColor.rgb = pow(fragColor.rgb * 0.7, vec3(1.0 / 2.2));
}