本文整理汇总了C++中Light::SampleL方法的典型用法代码示例。如果您正苦于以下问题：C++ Light::SampleL方法的具体用法？C++ Light::SampleL怎么用？C++ Light::SampleL使用的例子？那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类Light的用法示例。
在下文中一共展示了Light::SampleL方法的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C++代码示例。
示例1: Li
u_int SingleScattering::Li(const Scene &scene, const Ray &ray,
const Sample &sample, SWCSpectrum *Lv, float *alpha) const
{
*Lv = 0.f;
Region *vr = scene.volumeRegion;
float t0, t1;
if (!vr || !vr->IntersectP(ray, &t0, &t1))
return 0;
// Do single scattering volume integration in _vr_
// Prepare for volume integration stepping
const float length = ray.d.Length();
const u_int N = Ceil2UInt((t1 - t0) * length / stepSize);
const float step = (t1 - t0) / N;
const SpectrumWavelengths &sw(sample.swl);
SWCSpectrum Tr(1.f);
const Vector w(-ray.d / length);
t0 += sample.sampler->GetOneD(sample, tauSampleOffset, 0) * step;
Ray r(ray(t0), ray.d, 0.f, step, ray.time);
const u_int nLights = scene.lights.size();
const u_int lightNum = min(nLights - 1,
Floor2UInt(sample.sampler->GetOneD(sample, scatterSampleOffset, 0) * nLights));
Light *light = scene.lights[lightNum];
// Compute sample patterns for single scattering samples
// FIXME - use real samples
float *samp = static_cast<float *>(alloca(3 * N * sizeof(float)));
LatinHypercube(*(sample.rng), samp, N, 3);
u_int sampOffset = 0;
DifferentialGeometry dg;
dg.p = r.o;
dg.nn = Normal(w);
for (u_int i = 0; i < N; ++i) {
// Ray is already offset above, no need to do it again
const SWCSpectrum stepTau(vr->Tau(sw, r, .5f * stepSize, 0.f));
Tr *= Exp(-stepTau);
// Possibly terminate raymarching if transmittance is small
if (Tr.Filter(sw) < 1e-3f) {
const float continueProb = .5f;
if (sample.rng->floatValue() > continueProb)
break; // TODO - REFACT - remove and add random value from sample
Tr /= continueProb;
}
// Compute single-scattering source term at _p_
*Lv += Tr * vr->Lve(sw, dg);
if (nLights > 0) {
const SWCSpectrum ss(vr->SigmaS(sw, dg));
if (!ss.Black()) {
// Add contribution of _light_ due to scattering at _p_
float pdf;
float u1 = samp[sampOffset], u2 = samp[sampOffset + 1],
u3 = samp[sampOffset + 2];
BSDF *ibsdf;
SWCSpectrum L;
if (light->SampleL(scene, sample, r.o, u1, u2, u3,
&ibsdf, NULL, &pdf, &L)) {
if (Connect(scene, sample, vr, true, false,
r.o, ibsdf->dgShading.p, false, &L,
NULL, NULL)) {
const Vector wo(Normalize(r.o - ibsdf->dgShading.p));
*Lv += Tr * ss * L *
ibsdf->F(sw, Vector(ibsdf->dgShading.nn), wo, false) *
(vr->P(sw, dg, w, wo) *
nLights);
}
}
}
}
sampOffset += 3;
// Advance to sample at _t0_ and update _T_
t0 += step;
r.o = ray(t0);
dg.p = r.o;
}
*Lv *= step * length;
return light->group;
}