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fixed suboptimal sampling when using roughdielectric with the phong microfacet distribution (reported by Benedikt Bitterli)

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Wenzel Jakob 2014-04-26 17:19:27 +02:00
parent 4763f7016a
commit 3b1f6dc257
1 changed files with 25 additions and 22 deletions
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47
src/bsdfs/roughdielectric.cpp
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@ -384,10 +384,8 @@ public:
H *= math::signum(Frame::cosTheta(H));
/* Evaluate the roughness */
Float alphaU = m_distribution.transformRoughness(
m_alphaU->eval(bRec.its).average()),
alphaV = m_distribution.transformRoughness(
m_alphaV->eval(bRec.its).average());
Float alphaU = m_alphaU->eval(bRec.its).average(),
alphaV = m_alphaV->eval(bRec.its).average();
#if ENLARGE_LOBE_TRICK == 1
Float factor = (1.2f - 0.2f * std::sqrt(
@ -395,6 +393,9 @@ public:
alphaU *= factor; alphaV *= factor;
#endif
alphaU = m_distribution.transformRoughness(alphaU);
alphaV = m_distribution.transformRoughness(alphaV);
/* Evaluate the microsurface normal sampling density */
Float prob = m_distribution.pdf(H, alphaU, alphaV);
@ -419,21 +420,22 @@ public:
return Spectrum(0.0f);
/* Evaluate the roughness */
Float alphaU = m_distribution.transformRoughness(
m_alphaU->eval(bRec.its).average()),
alphaV = m_distribution.transformRoughness(
m_alphaV->eval(bRec.its).average());
Float alphaU = m_alphaU->eval(bRec.its).average(),
alphaV = m_alphaV->eval(bRec.its).average(),
sampleAlphaU = alphaU,
sampleAlphaV = alphaV;
#if ENLARGE_LOBE_TRICK == 1
Float factor = (1.2f - 0.2f * std::sqrt(
std::abs(Frame::cosTheta(bRec.wi))));
Float sampleAlphaU = alphaU * factor,
sampleAlphaV = alphaV * factor;
#else
Float sampleAlphaU = alphaU,
sampleAlphaV = alphaV;
sampleAlphaU *= factor; sampleAlphaV *= factor;
#endif
alphaU = m_distribution.transformRoughness(alphaU);
alphaV = m_distribution.transformRoughness(alphaV);
sampleAlphaU = m_distribution.transformRoughness(sampleAlphaU);
sampleAlphaV = m_distribution.transformRoughness(sampleAlphaV);
/* Sample M, the microsurface normal */
Float microfacetPDF;
const Normal m = m_distribution.sample(sample,
@ -510,21 +512,22 @@ public:
return Spectrum(0.0f);
/* Evaluate the roughness */
Float alphaU = m_distribution.transformRoughness(
m_alphaU->eval(bRec.its).average()),
alphaV = m_distribution.transformRoughness(
m_alphaV->eval(bRec.its).average());
Float alphaU = m_alphaU->eval(bRec.its).average(),
alphaV = m_alphaV->eval(bRec.its).average(),
sampleAlphaU = alphaU,
sampleAlphaV = alphaV;
#if ENLARGE_LOBE_TRICK == 1
Float factor = (1.2f - 0.2f * std::sqrt(
std::abs(Frame::cosTheta(bRec.wi))));
Float sampleAlphaU = alphaU * factor,
sampleAlphaV = alphaV * factor;
#else
Float sampleAlphaU = alphaU,
sampleAlphaV = alphaV;
sampleAlphaU *= factor; sampleAlphaV *= factor;
#endif
alphaU = m_distribution.transformRoughness(alphaU);
alphaV = m_distribution.transformRoughness(alphaV);
sampleAlphaU = m_distribution.transformRoughness(sampleAlphaU);
sampleAlphaV = m_distribution.transformRoughness(sampleAlphaV);
/* Sample M, the microsurface normal */
Float microfacetPDF;
const Normal m = m_distribution.sample(sample,