public void getSamples(ShadingState state)
{
if (Vector3.dot(dir, state.getGeoNormal()) < 0 && Vector3.dot(dir, state.getNormal()) < 0)
{
// project point onto source plane
float x = state.getPoint().x - src.x;
float y = state.getPoint().y - src.y;
float z = state.getPoint().z - src.z;
float t = ((x * dir.x) + (y * dir.y) + (z * dir.z));
if (t >= 0.0)
{
x -= (t * dir.x);
y -= (t * dir.y);
z -= (t * dir.z);
if (((x * x) + (y * y) + (z * z)) <= r2)
{
Point3 p = new Point3();
p.x = src.x + x;
p.y = src.y + y;
p.z = src.z + z;
LightSample dest = new LightSample();
dest.setShadowRay(new Ray(state.getPoint(), p));
dest.setRadiance(radiance, radiance);
dest.traceShadow(state);
state.addSample(dest);
}
}
}
}
public void getSamples(ShadingState state)
{
Vector3 d = Point3.sub(lightPoint, state.getPoint(), new Vector3());
if (Vector3.dot(d, state.getNormal()) > 0 && Vector3.dot(d, state.getGeoNormal()) > 0)
{
LightSample dest = new LightSample();
// prepare shadow ray
dest.setShadowRay(new Ray(state.getPoint(), lightPoint));
float scale = 1.0f / (float)(4 * Math.PI * lightPoint.distanceToSquared(state.getPoint()));
dest.setRadiance(power, power);
dest.getDiffuseRadiance().mul(scale);
dest.getSpecularRadiance().mul(scale);
dest.traceShadow(state);
state.addSample(dest);
}
}
public void getSamples(ShadingState state)
{
if (storedPhotons == 0)
return;
NearestPhotons np = new NearestPhotons(state.getPoint(), gatherNum, gatherRadius * gatherRadius);
locatePhotons(np);
if (np.found < 8)
return;
Point3 ppos = new Point3();
Vector3 pdir = new Vector3();
Vector3 pvec = new Vector3();
float invArea = 1.0f / ((float)Math.PI * np.dist2[0]);
float maxNDist = np.dist2[0] * 0.05f;
float f2r2 = 1.0f / (filterValue * filterValue * np.dist2[0]);
float fInv = 1.0f / (1.0f - 2.0f / (3.0f * filterValue));
for (int i = 1; i <= np.found; i++)
{
Photon phot = np.index[i];
Vector3.decode(phot.dir, pdir);
float cos = -Vector3.dot(pdir, state.getNormal());
if (cos > 0.001)
{
ppos.set(phot.x, phot.y, phot.z);
Point3.sub(ppos, state.getPoint(), pvec);
float pcos = Vector3.dot(pvec, state.getNormal());
if ((pcos < maxNDist) && (pcos > -maxNDist))
{
LightSample sample = new LightSample();
sample.setShadowRay(new Ray(state.getPoint(), pdir.negate()));
sample.setRadiance(new Color().setRGBE(np.index[i].power).mul(invArea / cos), Color.BLACK);
sample.getDiffuseRadiance().mul((1.0f - (float)Math.Sqrt(np.dist2[i] * f2r2)) * fInv);
state.addSample(sample);
}
}
}
}
public void getSamples(ShadingState state)
{
if (samples == null)
{
int n = state.getDiffuseDepth() > 0 ? 1 : numSamples;
for (int i = 0; i < n; i++)
{
// random offset on unit square, we use the infinite version of
// getRandom because the light sampling is adaptive
double randX = state.getRandom(i, 0, n);
double randY = state.getRandom(i, 1, n);
int x = 0;
while (randX >= colHistogram[x] && x < colHistogram.Length - 1)
x++;
float[] rowHistogram = imageHistogram[x];
int y = 0;
while (randY >= rowHistogram[y] && y < rowHistogram.Length - 1)
y++;
// sample from (x, y)
float u = (float)((x == 0) ? (randX / colHistogram[0]) : ((randX - colHistogram[x - 1]) / (colHistogram[x] - colHistogram[x - 1])));
float v = (float)((y == 0) ? (randY / rowHistogram[0]) : ((randY - rowHistogram[y - 1]) / (rowHistogram[y] - rowHistogram[y - 1])));
float px = ((x == 0) ? colHistogram[0] : (colHistogram[x] - colHistogram[x - 1]));
float py = ((y == 0) ? rowHistogram[0] : (rowHistogram[y] - rowHistogram[y - 1]));
float su = (x + u) / colHistogram.Length;
float sv = (y + v) / rowHistogram.Length;
float invP = (float)Math.Sin(sv * Math.PI) * jacobian / (n * px * py);
Vector3 dir = getDirection(su, sv);
basis.transform(dir);
if (Vector3.dot(dir, state.getGeoNormal()) > 0)
{
LightSample dest = new LightSample();
dest.setShadowRay(new Ray(state.getPoint(), dir));
dest.getShadowRay().setMax(float.MaxValue);
Color radiance = texture.getPixel(su, sv);
dest.setRadiance(radiance, radiance);
dest.getDiffuseRadiance().mul(invP);
dest.getSpecularRadiance().mul(invP);
dest.traceShadow(state);
state.addSample(dest);
}
}
}
else
{
for (int i = 0; i < numSamples; i++)
{
if (Vector3.dot(samples[i], state.getGeoNormal()) > 0 && Vector3.dot(samples[i], state.getNormal()) > 0)
{
LightSample dest = new LightSample();
dest.setShadowRay(new Ray(state.getPoint(), samples[i]));
dest.getShadowRay().setMax(float.MaxValue);
dest.setRadiance(colors[i], colors[i]);
dest.traceShadow(state);
state.addSample(dest);
}
}
}
}
public void getSamples(ShadingState state)
{
if (meshlight.numSamples == 0)
return;
Vector3 n = state.getNormal();
Point3 p = state.getPoint();
// vector towards each vertex of the light source
Vector3 p0 = Point3.sub(meshlight.getPoint(meshlight.triangles[tri3 + 0]), p, new Vector3());
// cull triangle if it is facing the wrong way
if (Vector3.dot(p0, ng) >= 0)
return;
Vector3 p1 = Point3.sub(meshlight.getPoint(meshlight.triangles[tri3 + 1]), p, new Vector3());
Vector3 p2 = Point3.sub(meshlight.getPoint(meshlight.triangles[tri3 + 2]), p, new Vector3());
// if all three vertices are below the hemisphere, stop
if (Vector3.dot(p0, n) <= 0 && Vector3.dot(p1, n) <= 0 && Vector3.dot(p2, n) <= 0)
return;
p0.normalize();
p1.normalize();
p2.normalize();
float dot = Vector3.dot(p2, p0);
Vector3 h = new Vector3();
h.x = p2.x - dot * p0.x;
h.y = p2.y - dot * p0.y;
h.z = p2.z - dot * p0.z;
float hlen = h.Length();
if (hlen > 1e-6f)
h.div(hlen);
else
return;
Vector3 n0 = Vector3.cross(p0, p1, new Vector3());
float len0 = n0.Length();
if (len0 > 1e-6f)
n0.div(len0);
else
return;
Vector3 n1 = Vector3.cross(p1, p2, new Vector3());
float len1 = n1.Length();
if (len1 > 1e-6f)
n1.div(len1);
else
return;
Vector3 n2 = Vector3.cross(p2, p0, new Vector3());
float len2 = n2.Length();
if (len2 > 1e-6f)
n2.div(len2);
else
return;
float cosAlpha = MathUtils.clamp(-Vector3.dot(n2, n0), -1.0f, 1.0f);
float cosBeta = MathUtils.clamp(-Vector3.dot(n0, n1), -1.0f, 1.0f);
float cosGamma = MathUtils.clamp(-Vector3.dot(n1, n2), -1.0f, 1.0f);
float alpha = (float)Math.Acos(cosAlpha);
float beta = (float)Math.Acos(cosBeta);
float gamma = (float)Math.Acos(cosGamma);
float area = alpha + beta + gamma - (float)Math.PI;
float cosC = MathUtils.clamp(Vector3.dot(p0, p1), -1.0f, 1.0f);
float salpha = (float)Math.Sin(alpha);
float product = salpha * cosC;
// use lower sampling depth for diffuse bounces
int samples = state.getDiffuseDepth() > 0 ? 1 : meshlight.numSamples;
Color c = Color.mul(area / samples, meshlight.radiance);
for (int i = 0; i < samples; i++)
{
// random offset on unit square
double randX = state.getRandom(i, 0, samples);
double randY = state.getRandom(i, 1, samples);
float phi = (float)randX * area - alpha + (float)Math.PI;
float sinPhi = (float)Math.Sin(phi);
float cosPhi = (float)Math.Cos(phi);
float u = cosPhi + cosAlpha;
float v = sinPhi - product;
float q = (-v + cosAlpha * (cosPhi * -v + sinPhi * u)) / (salpha * (sinPhi * -v - cosPhi * u));
float q1 = 1.0f - q * q;
if (q1 < 0.0f)
q1 = 0.0f;
float sqrtq1 = (float)Math.Sqrt(q1);
float ncx = q * p0.x + sqrtq1 * h.x;
float ncy = q * p0.y + sqrtq1 * h.y;
float ncz = q * p0.z + sqrtq1 * h.z;
dot = p1.dot(ncx, ncy, ncz);
float z = 1.0f - (float)randY * (1.0f - dot);
float z1 = 1.0f - z * z;
if (z1 < 0.0f)
z1 = 0.0f;
Vector3 nd = new Vector3();
nd.x = ncx - dot * p1.x;
nd.y = ncy - dot * p1.y;
nd.z = ncz - dot * p1.z;
nd.normalize();
float sqrtz1 = (float)Math.Sqrt(z1);
Vector3 result = new Vector3();
result.x = z * p1.x + sqrtz1 * nd.x;
result.y = z * p1.y + sqrtz1 * nd.y;
result.z = z * p1.z + sqrtz1 * nd.z;
// make sure the sample is in the right hemisphere - facing in
// the right direction
if (Vector3.dot(result, n) > 0 && Vector3.dot(result, state.getGeoNormal()) > 0 && Vector3.dot(result, ng) < 0)
{
// compute intersection with triangle (if any)
Ray shadowRay = new Ray(state.getPoint(), result);
if (!intersectTriangleKensler(shadowRay))
continue;
LightSample dest = new LightSample();
dest.setShadowRay(shadowRay);
// prepare sample
dest.setRadiance(c, c);
dest.traceShadow(state);
state.addSample(dest);
}
}
}
public void getSamples(ShadingState state)
{
if (getNumSamples() <= 0)
return;
Vector3 wc = Point3.sub(center, state.getPoint(), new Vector3());
float l2 = wc.LengthSquared();
if (l2 <= r2)
return; // inside the sphere?
// top of the sphere as viewed from the current shading point
float topX = wc.x + state.getNormal().x * radius;
float topY = wc.y + state.getNormal().y * radius;
float topZ = wc.z + state.getNormal().z * radius;
if (state.getNormal().dot(topX, topY, topZ) <= 0)
return; // top of the sphere is below the horizon
float cosThetaMax = (float)Math.Sqrt(Math.Max(0, 1 - r2 / Vector3.dot(wc, wc)));
OrthoNormalBasis basis = OrthoNormalBasis.makeFromW(wc);
int samples = state.getDiffuseDepth() > 0 ? 1 : getNumSamples();
float scale = (float)(2 * Math.PI * (1 - cosThetaMax));
Color c = Color.mul(scale / samples, radiance);
for (int i = 0; i < samples; i++)
{
// random offset on unit square
double randX = state.getRandom(i, 0, samples);
double randY = state.getRandom(i, 1, samples);
// cone sampling
double cosTheta = (1 - randX) * cosThetaMax + randX;
double sinTheta = Math.Sqrt(1 - cosTheta * cosTheta);
double phi = randY * 2 * Math.PI;
Vector3 dir = new Vector3((float)(Math.Cos(phi) * sinTheta), (float)(Math.Sin(phi) * sinTheta), (float)cosTheta);
basis.transform(dir);
// check that the direction of the sample is the same as the
// normal
float cosNx = Vector3.dot(dir, state.getNormal());
if (cosNx <= 0)
continue;
float ocx = state.getPoint().x - center.x;
float ocy = state.getPoint().y - center.y;
float ocz = state.getPoint().z - center.z;
float qa = Vector3.dot(dir, dir);
float qb = 2 * ((dir.x * ocx) + (dir.y * ocy) + (dir.z * ocz));
float qc = ((ocx * ocx) + (ocy * ocy) + (ocz * ocz)) - r2;
double[] t = Solvers.solveQuadric(qa, qb, qc);
if (t == null)
continue;
LightSample dest = new LightSample();
// compute shadow ray to the sampled point
dest.setShadowRay(new Ray(state.getPoint(), dir));
// FIXME: arbitrary bias, should handle as in other places
dest.getShadowRay().setMax((float)t[0] - 1e-3f);
// prepare sample
dest.setRadiance(c, c);
dest.traceShadow(state);
state.addSample(dest);
}
}
public void getSamples(ShadingState state)
{
if (lightBounds.contains(state.getPoint()) && state.getPoint().z < maxZ)
{
int n = state.getDiffuseDepth() > 0 ? 1 : samples;
float a = area / n;
for (int i = 0; i < n; i++)
{
// random offset on unit square
double randX = state.getRandom(i, 0, n);
double randY = state.getRandom(i, 1, n);
Point3 p = new Point3();
p.x = (float)(lxmin * (1 - randX) + lxmax * randX);
p.y = (float)(lymin * (1 - randY) + lymax * randY);
p.z = maxZ - 0.001f;
LightSample dest = new LightSample();
// prepare shadow ray to sampled point
dest.setShadowRay(new Ray(state.getPoint(), p));
// check that the direction of the sample is the same as the
// normal
float cosNx = dest.dot(state.getNormal());
if (cosNx <= 0)
return;
// light source facing point ?
// (need to check with light source's normal)
float cosNy = dest.getShadowRay().dz;
if (cosNy > 0)
{
// compute geometric attenuation and probability scale
// factor
float r = dest.getShadowRay().getMax();
float g = cosNy / (r * r);
float scale = g * a;
// set sample radiance
dest.setRadiance(radiance, radiance);
dest.getDiffuseRadiance().mul(scale);
dest.getSpecularRadiance().mul(scale);
dest.traceShadow(state);
state.addSample(dest);
}
}
}
}
public LightSample next; // pointer to next item in a linked list of samples
/**
* Creates a new light sample object (invalid by default).
*/
public LightSample()
{
ldiff = lspec = null;
shadowRay = null;
next = null;
}
private Ray shadowRay; // ray to be used to evaluate if the point is in
#endregion Fields
#region Constructors
/**
* Creates a new light sample object (invalid by default).
*/
public LightSample()
{
ldiff = lspec = null;
shadowRay = null;
next = null;
}
