public void scatterPhoton(ShadingState state, Color power)
{
Color diffuse, specular;
// make sure we are on the right side of the material
state.faceforward();
diffuse = getDiffuse(state);
specular = getSpecular(state);
state.storePhoton(state.getRay().getDirection(), power, diffuse);
float d = diffuse.getAverage();
float r = specular.getAverage();
double rnd = state.getRandom(0, 0, 1);
if (rnd < d)
{
// photon is scattered
power.mul(diffuse).mul(1.0f / d);
OrthoNormalBasis onb = state.getBasis();
double u = 2 * Math.PI * rnd / d;
double v = state.getRandom(0, 1, 1);
float s = (float)Math.Sqrt(v);
float s1 = (float)Math.Sqrt(1.0 - v);
Vector3 w = new Vector3((float)Math.Cos(u) * s, (float)Math.Sin(u) * s, s1);
w = onb.transform(w, new Vector3());
state.traceDiffusePhoton(new Ray(state.getPoint(), w), power);
}
else if (rnd < d + r)
{
if (glossyness == 0)
{
float cos = -Vector3.dot(state.getNormal(), state.getRay().getDirection());
power.mul(diffuse).mul(1.0f / d);
// photon is reflected
float dn = 2 * cos;
Vector3 dir = new Vector3();
dir.x = (dn * state.getNormal().x) + state.getRay().getDirection().x;
dir.y = (dn * state.getNormal().y) + state.getRay().getDirection().y;
dir.z = (dn * state.getNormal().z) + state.getRay().getDirection().z;
state.traceReflectionPhoton(new Ray(state.getPoint(), dir), power);
}
else
{
float dn = 2.0f * state.getCosND();
// reflected direction
Vector3 refDir = new Vector3();
refDir.x = (dn * state.getNormal().x) + state.getRay().dx;
refDir.y = (dn * state.getNormal().y) + state.getRay().dy;
refDir.z = (dn * state.getNormal().z) + state.getRay().dz;
power.mul(spec).mul(1.0f / r);
OrthoNormalBasis onb = state.getBasis();
double u = 2 * Math.PI * (rnd - r) / r;
double v = state.getRandom(0, 1, 1);
float s = (float)Math.Pow(v, 1 / ((1.0f / glossyness) + 1));
float s1 = (float)Math.Sqrt(1 - s * s);
Vector3 w = new Vector3((float)Math.Cos(u) * s1, (float)Math.Sin(u) * s1, s);
w = onb.transform(w, new Vector3());
state.traceReflectionPhoton(new Ray(state.getPoint(), w), power);
}
}
}
public void ScatterPhoton(ShadingState state, Color power)
{
float avg = color.getAverage();
double rnd = state.getRandom(0, 0, 1);
if (rnd >= avg)
return;
state.faceforward();
float cos = state.getCosND();
power.mul(color).mul(1.0f / avg);
// photon is reflected
float dn = 2 * cos;
Vector3 dir = new Vector3();
dir.x = (dn * state.getNormal().x) + state.getRay().getDirection().x;
dir.y = (dn * state.getNormal().y) + state.getRay().getDirection().y;
dir.z = (dn * state.getNormal().z) + state.getRay().getDirection().z;
state.traceReflectionPhoton(new Ray(state.getPoint(), dir), power);
}
public void scatterPhoton(ShadingState state, Color power)
{
// make sure we are on the right side of the material
state.faceforward();
Color d = getDiffuse(state);
state.storePhoton(state.getRay().getDirection(), power, d);
float avgD = d.getAverage();
float avgS = spec.getAverage();
double rnd = state.getRandom(0, 0, 1);
if (rnd < avgD)
{
// photon is scattered diffusely
power.mul(d).mul(1.0f / avgD);
OrthoNormalBasis onb = state.getBasis();
double u = 2 * Math.PI * rnd / avgD;
double v = state.getRandom(0, 1, 1);
float s = (float)Math.Sqrt(v);
float s1 = (float)Math.Sqrt(1.0f - v);
Vector3 w = new Vector3((float)Math.Cos(u) * s, (float)Math.Sin(u) * s, s1);
w = onb.transform(w, new Vector3());
state.traceDiffusePhoton(new Ray(state.getPoint(), w), power);
}
else if (rnd < avgD + avgS)
{
// photon is scattered specularly
float dn = 2.0f * state.getCosND();
// reflected direction
Vector3 refDir = new Vector3();
refDir.x = (dn * state.getNormal().x) + state.getRay().dx;
refDir.y = (dn * state.getNormal().y) + state.getRay().dy;
refDir.z = (dn * state.getNormal().z) + state.getRay().dz;
power.mul(spec).mul(1.0f / avgS);
OrthoNormalBasis onb = state.getBasis();
double u = 2 * Math.PI * (rnd - avgD) / avgS;
double v = state.getRandom(0, 1, 1);
float s = (float)Math.Pow(v, 1 / (this.power + 1));
float s1 = (float)Math.Sqrt(1 - s * s);
Vector3 w = new Vector3((float)Math.Cos(u) * s1, (float)Math.Sin(u) * s1, s);
w = onb.transform(w, new Vector3());
state.traceReflectionPhoton(new Ray(state.getPoint(), w), power);
}
}
public void scatterPhoton(ShadingState state, Color power)
{
float avg = color.getAverage();
double rnd = state.getRandom(0, 0, 1);
if (rnd >= avg)
{
return;
}
state.faceforward();
float cos = state.getCosND();
power.mul(color).mul(1.0f / avg);
// photon is reflected
float dn = 2 * cos;
Vector3 dir = new Vector3();
dir.x = (dn * state.getNormal().x) + state.getRay().getDirection().x;
dir.y = (dn * state.getNormal().y) + state.getRay().getDirection().y;
dir.z = (dn * state.getNormal().z) + state.getRay().getDirection().z;
state.traceReflectionPhoton(new Ray(state.getPoint(), dir), power);
}
public void scatterPhoton(ShadingState state, Color power)
{
Color diffuse;
// make sure we are on the right side of the material
state.faceforward();
diffuse = getDiffuse(state);
state.storePhoton(state.getRay().getDirection(), power, diffuse);
float d = diffuse.getAverage();
float r = d * refl;
double rnd = state.getRandom(0, 0, 1);
if (rnd < d)
{
// photon is scattered
power.mul(diffuse).mul(1.0f / d);
OrthoNormalBasis onb = state.getBasis();
double u = 2 * Math.PI * rnd / d;
double v = state.getRandom(0, 1, 1);
float s = (float)Math.Sqrt(v);
float s1 = (float)Math.Sqrt(1.0 - v);
Vector3 w = new Vector3((float)Math.Cos(u) * s, (float)Math.Sin(u) * s, s1);
w = onb.transform(w, new Vector3());
state.traceDiffusePhoton(new Ray(state.getPoint(), w), power);
}
else if (rnd < d + r)
{
float cos = -Vector3.dot(state.getNormal(), state.getRay().getDirection());
power.mul(diffuse).mul(1.0f / d);
// photon is reflected
float dn = 2 * cos;
Vector3 dir = new Vector3();
dir.x = (dn * state.getNormal().x) + state.getRay().getDirection().x;
dir.y = (dn * state.getNormal().y) + state.getRay().getDirection().y;
dir.z = (dn * state.getNormal().z) + state.getRay().getDirection().z;
state.traceReflectionPhoton(new Ray(state.getPoint(), dir), power);
}
}
public void ScatterPhoton(ShadingState state, Color power)
{
Color diffuse, specular;
// make sure we are on the right side of the material
state.faceforward();
diffuse = getDiffuse(state);
specular = getSpecular(state);
state.storePhoton(state.getRay().getDirection(), power, diffuse);
float d = diffuse.getAverage();
float r = specular.getAverage();
double rnd = state.getRandom(0, 0, 1);
if (rnd < d)
{
// photon is scattered
power.mul(diffuse).mul(1.0f / d);
OrthoNormalBasis onb = state.getBasis();
double u = 2 * Math.PI * rnd / d;
double v = state.getRandom(0, 1, 1);
float s = (float)Math.Sqrt(v);
float s1 = (float)Math.Sqrt(1.0 - v);
Vector3 w = new Vector3((float)Math.Cos(u) * s, (float)Math.Sin(u) * s, s1);
w = onb.transform(w, new Vector3());
state.traceDiffusePhoton(new Ray(state.getPoint(), w), power);
}
else if (rnd < d + r)
{
if (glossyness == 0)
{
float cos = -Vector3.dot(state.getNormal(), state.getRay().getDirection());
power.mul(diffuse).mul(1.0f / d);
// photon is reflected
float dn = 2 * cos;
Vector3 dir = new Vector3();
dir.x = (dn * state.getNormal().x) + state.getRay().getDirection().x;
dir.y = (dn * state.getNormal().y) + state.getRay().getDirection().y;
dir.z = (dn * state.getNormal().z) + state.getRay().getDirection().z;
state.traceReflectionPhoton(new Ray(state.getPoint(), dir), power);
}
else
{
float dn = 2.0f * state.getCosND();
// reflected direction
Vector3 refDir = new Vector3();
refDir.x = (dn * state.getNormal().x) + state.getRay().dx;
refDir.y = (dn * state.getNormal().y) + state.getRay().dy;
refDir.z = (dn * state.getNormal().z) + state.getRay().dz;
power.mul(spec).mul(1.0f / r);
OrthoNormalBasis onb = state.getBasis();
double u = 2 * Math.PI * (rnd - r) / r;
double v = state.getRandom(0, 1, 1);
float s = (float)Math.Pow(v, 1 / ((1.0f / glossyness) + 1));
float s1 = (float)Math.Sqrt(1 - s * s);
Vector3 w = new Vector3((float)Math.Cos(u) * s1, (float)Math.Sin(u) * s1, s);
w = onb.transform(w, new Vector3());
state.traceReflectionPhoton(new Ray(state.getPoint(), w), power);
}
}
}
public void scatterPhoton(ShadingState state, Color power)
{
// make sure we are on the right side of the material
state.faceforward();
Color d = getDiffuse(state);
state.storePhoton(state.getRay().getDirection(), power, d);
float avgD = d.getAverage();
float avgS = rhoS.getAverage();
double rnd = state.getRandom(0, 0, 1);
if (rnd < avgD)
{
// photon is scattered diffusely
power.mul(d).mul(1.0f / avgD);
OrthoNormalBasis onb = state.getBasis();
double u = 2 * Math.PI * rnd / avgD;
double v = state.getRandom(0, 1, 1);
float s = (float)Math.Sqrt(v);
float s1 = (float)Math.Sqrt(1.0f - v);
Vector3 w = new Vector3((float)Math.Cos(u) * s, (float)Math.Sin(u) * s, s1);
w = onb.transform(w, new Vector3());
state.traceDiffusePhoton(new Ray(state.getPoint(), w), power);
}
else if (rnd < avgD + avgS)
{
// photon is scattered specularly
power.mul(rhoS).mul(1 / avgS);
OrthoNormalBasis basis = state.getBasis();
Vector3 inv = state.getRay().getDirection().negate(new Vector3());
double r1 = rnd / avgS;
double r2 = state.getRandom(0, 1, 1);
float alphaRatio = alphaY / alphaX;
float phi = 0;
if (r1 < 0.25)
{
double val = 4 * r1;
phi = (float)Math.Atan(alphaRatio * Math.Tan(Math.PI / 2 * val));
}
else if (r1 < 0.5)
{
double val = 1 - 4 * (0.5 - r1);
phi = (float)Math.Atan(alphaRatio * Math.Tan(Math.PI / 2 * val));
phi = (float)Math.PI - phi;
}
else if (r1 < 0.75)
{
double val = 4 * (r1 - 0.5);
phi = (float)Math.Atan(alphaRatio * Math.Tan(Math.PI / 2 * val));
phi += (float)Math.PI;
}
else
{
double val = 1 - 4 * (1 - r1);
phi = (float)Math.Atan(alphaRatio * Math.Tan(Math.PI / 2 * val));
phi = 2 * (float)Math.PI - phi;
}
float cosPhi = (float)Math.Cos(phi);
float sinPhi = (float)Math.Sin(phi);
float denom = (cosPhi * cosPhi) / (alphaX * alphaX) + (sinPhi * sinPhi) / (alphaY * alphaY);
float theta = (float)Math.Atan(Math.Sqrt(-Math.Log(1 - r2) / denom));
float sinTheta = (float)Math.Sin(theta);
float cosTheta = (float)Math.Cos(theta);
Vector3 h = new Vector3();
h.x = sinTheta * cosPhi;
h.y = sinTheta * sinPhi;
h.z = cosTheta;
basis.transform(h);
Vector3 o = new Vector3();
float ih = Vector3.dot(h, inv);
o.x = 2 * ih * h.x - inv.x;
o.y = 2 * ih * h.y - inv.y;
o.z = 2 * ih * h.z - inv.z;
Ray r = new Ray(state.getPoint(), o);
state.traceReflectionPhoton(r, power);
}
}
public void ScatterPhoton(ShadingState state, Color power)
{
Color diffuse;
// make sure we are on the right side of the material
state.faceforward();
diffuse = getDiffuse(state);
state.storePhoton(state.getRay().getDirection(), power, diffuse);
float d = diffuse.getAverage();
float r = d * refl;
double rnd = state.getRandom(0, 0, 1);
if (rnd < d)
{
// photon is scattered
power.mul(diffuse).mul(1.0f / d);
OrthoNormalBasis onb = state.getBasis();
double u = 2 * Math.PI * rnd / d;
double v = state.getRandom(0, 1, 1);
float s = (float)Math.Sqrt(v);
float s1 = (float)Math.Sqrt(1.0 - v);
Vector3 w = new Vector3((float)Math.Cos(u) * s, (float)Math.Sin(u) * s, s1);
w = onb.transform(w, new Vector3());
state.traceDiffusePhoton(new Ray(state.getPoint(), w), power);
}
else if (rnd < d + r)
{
float cos = -Vector3.dot(state.getNormal(), state.getRay().getDirection());
power.mul(diffuse).mul(1.0f / d);
// photon is reflected
float dn = 2 * cos;
Vector3 dir = new Vector3();
dir.x = (dn * state.getNormal().x) + state.getRay().getDirection().x;
dir.y = (dn * state.getNormal().y) + state.getRay().getDirection().y;
dir.z = (dn * state.getNormal().z) + state.getRay().getDirection().z;
state.traceReflectionPhoton(new Ray(state.getPoint(), dir), power);
}
}
public void ScatterPhoton(ShadingState state, Color power)
{
Color refr = Color.mul(1 - f0, color);
Color refl = Color.mul(f0, color);
float avgR = refl.getAverage();
float avgT = refr.getAverage();
double rnd = state.getRandom(0, 0, 1);
if (rnd < avgR)
{
state.faceforward();
// don't reflect internally
if (state.isBehind())
return;
// photon is reflected
float cos = state.getCosND();
power.mul(refl).mul(1.0f / avgR);
float dn = 2 * cos;
Vector3 dir = new Vector3();
dir.x = (dn * state.getNormal().x) + state.getRay().getDirection().x;
dir.y = (dn * state.getNormal().y) + state.getRay().getDirection().y;
dir.z = (dn * state.getNormal().z) + state.getRay().getDirection().z;
state.traceReflectionPhoton(new Ray(state.getPoint(), dir), power);
}
else if (rnd < avgR + avgT)
{
state.faceforward();
// photon is refracted
float cos = state.getCosND();
float neta = state.isBehind() ? eta : 1.0f / eta;
power.mul(refr).mul(1.0f / avgT);
float wK = -neta;
float arg = 1 - (neta * neta * (1 - (cos * cos)));
Vector3 dir = new Vector3();
if (state.isBehind() && absorptionDistance > 0)
{
// this ray is inside the object and leaving it
// compute attenuation that occured along the ray
power.mul(Color.mul(-state.getRay().getMax() / absorptionDistance, absorptionColor.copy().opposite()).exp());
}
if (arg < 0)
{
// TIR
float dn = 2 * cos;
dir.x = (dn * state.getNormal().x) + state.getRay().getDirection().x;
dir.y = (dn * state.getNormal().y) + state.getRay().getDirection().y;
dir.z = (dn * state.getNormal().z) + state.getRay().getDirection().z;
state.traceReflectionPhoton(new Ray(state.getPoint(), dir), power);
}
else
{
float nK = (neta * cos) - (float)Math.Sqrt(arg);
dir.x = (-wK * state.getRay().dx) + (nK * state.getNormal().x);
dir.y = (-wK * state.getRay().dy) + (nK * state.getNormal().y);
dir.z = (-wK * state.getRay().dz) + (nK * state.getNormal().z);
state.traceRefractionPhoton(new Ray(state.getPoint(), dir), power);
}
}
}
public void ScatterPhoton(ShadingState state, Color power)
{
// make sure we are on the right side of the material
state.faceforward();
Color d = getDiffuse(state);
state.storePhoton(state.getRay().getDirection(), power, d);
float avgD = d.getAverage();
float avgS = rhoS.getAverage();
double rnd = state.getRandom(0, 0, 1);
if (rnd < avgD)
{
// photon is scattered diffusely
power.mul(d).mul(1.0f / avgD);
OrthoNormalBasis onb = state.getBasis();
double u = 2 * Math.PI * rnd / avgD;
double v = state.getRandom(0, 1, 1);
float s = (float)Math.Sqrt(v);
float s1 = (float)Math.Sqrt(1.0f - v);
Vector3 w = new Vector3((float)Math.Cos(u) * s, (float)Math.Sin(u) * s, s1);
w = onb.transform(w, new Vector3());
state.traceDiffusePhoton(new Ray(state.getPoint(), w), power);
}
else if (rnd < avgD + avgS)
{
// photon is scattered specularly
power.mul(rhoS).mul(1 / avgS);
OrthoNormalBasis basis = state.getBasis();
Vector3 inv = state.getRay().getDirection().negate(new Vector3());
double r1 = rnd / avgS;
double r2 = state.getRandom(0, 1, 1);
float alphaRatio = alphaY / alphaX;
float phi = 0;
if (r1 < 0.25)
{
double val = 4 * r1;
phi = (float)Math.Atan(alphaRatio * Math.Tan(Math.PI / 2 * val));
}
else if (r1 < 0.5)
{
double val = 1 - 4 * (0.5 - r1);
phi = (float)Math.Atan(alphaRatio * Math.Tan(Math.PI / 2 * val));
phi = (float)Math.PI - phi;
}
else if (r1 < 0.75)
{
double val = 4 * (r1 - 0.5);
phi = (float)Math.Atan(alphaRatio * Math.Tan(Math.PI / 2 * val));
phi += (float)Math.PI;
}
else
{
double val = 1 - 4 * (1 - r1);
phi = (float)Math.Atan(alphaRatio * Math.Tan(Math.PI / 2 * val));
phi = 2 * (float)Math.PI - phi;
}
float cosPhi = (float)Math.Cos(phi);
float sinPhi = (float)Math.Sin(phi);
float denom = (cosPhi * cosPhi) / (alphaX * alphaX) + (sinPhi * sinPhi) / (alphaY * alphaY);
float theta = (float)Math.Atan(Math.Sqrt(-Math.Log(1 - r2) / denom));
float sinTheta = (float)Math.Sin(theta);
float cosTheta = (float)Math.Cos(theta);
Vector3 h = new Vector3();
h.x = sinTheta * cosPhi;
h.y = sinTheta * sinPhi;
h.z = cosTheta;
basis.transform(h);
Vector3 o = new Vector3();
float ih = Vector3.dot(h, inv);
o.x = 2 * ih * h.x - inv.x;
o.y = 2 * ih * h.y - inv.y;
o.z = 2 * ih * h.z - inv.z;
Ray r = new Ray(state.getPoint(), o);
state.traceReflectionPhoton(r, power);
}
}
public void scatterPhoton(ShadingState state, Color power)
{
// make sure we are on the right side of the material
state.faceforward();
Color d = getDiffuse(state);
state.storePhoton(state.getRay().getDirection(), power, d);
float avgD = d.getAverage();
float avgS = spec.getAverage();
double rnd = state.getRandom(0, 0, 1);
if (rnd < avgD)
{
// photon is scattered diffusely
power.mul(d).mul(1.0f / avgD);
OrthoNormalBasis onb = state.getBasis();
double u = 2 * Math.PI * rnd / avgD;
double v = state.getRandom(0, 1, 1);
float s = (float)Math.Sqrt(v);
float s1 = (float)Math.Sqrt(1.0f - v);
Vector3 w = new Vector3((float)Math.Cos(u) * s, (float)Math.Sin(u) * s, s1);
w = onb.transform(w, new Vector3());
state.traceDiffusePhoton(new Ray(state.getPoint(), w), power);
}
else if (rnd < avgD + avgS)
{
// photon is scattered specularly
float dn = 2.0f * state.getCosND();
// reflected direction
Vector3 refDir = new Vector3();
refDir.x = (dn * state.getNormal().x) + state.getRay().dx;
refDir.y = (dn * state.getNormal().y) + state.getRay().dy;
refDir.z = (dn * state.getNormal().z) + state.getRay().dz;
power.mul(spec).mul(1.0f / avgS);
OrthoNormalBasis onb = state.getBasis();
double u = 2 * Math.PI * (rnd - avgD) / avgS;
double v = state.getRandom(0, 1, 1);
float s = (float)Math.Pow(v, 1 / (this.power + 1));
float s1 = (float)Math.Sqrt(1 - s * s);
Vector3 w = new Vector3((float)Math.Cos(u) * s1, (float)Math.Sin(u) * s1, s);
w = onb.transform(w, new Vector3());
state.traceReflectionPhoton(new Ray(state.getPoint(), w), power);
}
}
public void ScatterPhoton(ShadingState state, Color power)
{
Color refr = Color.mul(1 - f0, color);
Color refl = Color.mul(f0, color);
float avgR = refl.getAverage();
float avgT = refr.getAverage();
double rnd = state.getRandom(0, 0, 1);
if (rnd < avgR)
{
state.faceforward();
// don't reflect internally
if (state.isBehind())
{
return;
}
// photon is reflected
float cos = state.getCosND();
power.mul(refl).mul(1.0f / avgR);
float dn = 2 * cos;
Vector3 dir = new Vector3();
dir.x = (dn * state.getNormal().x) + state.getRay().getDirection().x;
dir.y = (dn * state.getNormal().y) + state.getRay().getDirection().y;
dir.z = (dn * state.getNormal().z) + state.getRay().getDirection().z;
state.traceReflectionPhoton(new Ray(state.getPoint(), dir), power);
}
else if (rnd < avgR + avgT)
{
state.faceforward();
// photon is refracted
float cos = state.getCosND();
float neta = state.isBehind() ? eta : 1.0f / eta;
power.mul(refr).mul(1.0f / avgT);
float wK = -neta;
float arg = 1 - (neta * neta * (1 - (cos * cos)));
Vector3 dir = new Vector3();
if (state.isBehind() && absorptionDistance > 0)
{
// this ray is inside the object and leaving it
// compute attenuation that occured along the ray
power.mul(Color.mul(-state.getRay().getMax() / absorptionDistance, absorptionColor.copy().opposite()).exp());
}
if (arg < 0)
{
// TIR
float dn = 2 * cos;
dir.x = (dn * state.getNormal().x) + state.getRay().getDirection().x;
dir.y = (dn * state.getNormal().y) + state.getRay().getDirection().y;
dir.z = (dn * state.getNormal().z) + state.getRay().getDirection().z;
state.traceReflectionPhoton(new Ray(state.getPoint(), dir), power);
}
else
{
float nK = (neta * cos) - (float)Math.Sqrt(arg);
dir.x = (-wK * state.getRay().dx) + (nK * state.getNormal().x);
dir.y = (-wK * state.getRay().dy) + (nK * state.getNormal().y);
dir.z = (-wK * state.getRay().dz) + (nK * state.getNormal().z);
state.traceRefractionPhoton(new Ray(state.getPoint(), dir), power);
}
}
}
