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 (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 (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);
}
}
}
}
