protected override RgbSpectrumInfo Evaluate(ref HitPointInfo HitPoint, ref Vector localLightDir, ref Vector localEyeDir, out BsdfEvent _event, out float directPdfW, out float reversePdfW)
{
_event = this.Type.TypeToEvent();
directPdfW = 0f;
reversePdfW = 0f;
return RgbSpectrumInfo.Black;
}
protected override RgbSpectrumInfo Evaluate(ref HitPointInfo HitPoint, ref Vector localLightDir, ref Vector localEyeDir, out BsdfEvent _event, out float directPdfW, out float reversePdfW)
{
_event = BsdfEvent.Diffuse | BsdfEvent.Reflect;
directPdfW = Math.Abs((HitPoint.FromLight ? localEyeDir.z : localLightDir.z) * MathLab.INVPI);
reversePdfW = Math.Abs((HitPoint.FromLight ? localLightDir.z : localEyeDir.z) * MathLab.INVPI);
var kd = TexData.Diffuse;
return (kd * MathLab.INVPI);
}
protected override RgbSpectrum Sample(ref HitPointInfo HitPoint, ref Vector localFixedDir, out Vector localSampledDir, float u0, float u1, out float pdfW, out float absCosDir, out BsdfEvent _event)
{
_event = this.Type.TypeToEvent();
localSampledDir = new Vector(-localFixedDir.x, -localFixedDir.y, localFixedDir.z);
pdfW = 1f;
absCosDir = Math.Abs(localSampledDir.z);
var kr = (RgbSpectrum)TexData.Specular;
// The absCosSampledDir is used to compensate the other one used inside the integrator
return kr / absCosDir;
}
protected override RgbSpectrum Sample(ref HitPointInfo HitPoint, ref Vector localFixedDir, out Vector localSampledDir, float u0, float u1, out float pdfW, out float absCosDir, out BsdfEvent _event)
{
absCosDir = 0f;
_event = BsdfEvent.Diffuse | BsdfEvent.Reflect;
pdfW = 0f;
localSampledDir = new Vector();
if (Math.Abs(localFixedDir.z) < MathLab.COS_EPSILON_STATIC)
return RgbSpectrum.ZeroSpectrum();
localSampledDir = Sgn(localFixedDir.z) * MC.CosineSampleHemisphere(u0, u1, out pdfW);
absCosDir = Math.Abs(localSampledDir.z);
if (absCosDir < MathLab.COS_EPSILON_STATIC)
return RgbSpectrum.ZeroSpectrum();
var kd = (RgbSpectrum)(TexData.Diffuse);
kd.Mul(MathLab.INVPI);
return (kd);
}
protected override RgbSpectrum Sample(ref HitPointInfo HitPoint, ref Vector localFixedDir, out Vector localSampledDir, float u0, float u1, out float pdfW, out float absCosDir, out BsdfEvent _event)
{
_event = this.Type.TypeToEvent();
localSampledDir = new Vector(-localFixedDir.x, -localFixedDir.y, localFixedDir.z);
pdfW = 1f;
absCosDir = Math.Abs(localSampledDir.z);
var kr = (RgbSpectrum)TexData.Specular;
float e = 1f / (Math.Max(TexData.Exponent, 0f) + 1f);
localSampledDir = GlossyReflection(ref localFixedDir, e, u0, u1);
if (localSampledDir.z * localFixedDir.z > 0f)
{
_event = BsdfEvent.Specular | BsdfEvent.Reflect;
pdfW = 1f;
absCosDir = Math.Abs(localSampledDir.z);
// The absCosSampledDir is used to compensate the other one used inside the integrator
return kr / (absCosDir);
}
else
return RgbSpectrum.ZeroSpectrum();
}
internal void Init(ref RayHit rh, ref RayData ray, ref Normal ng, ref Normal ns, ref UV texCoord,
MaterialInfo mi, SurfaceTextureInfo texData, bool fromLight)
{
if (rh.Miss())
{
throw new ArgumentException("RayHit missed geometry!");
}
//if (HitPoint == null)
//{
HitPoint = new HitPointInfo
{
Color = RgbSpectrum.Max(ref mi.Kd, ref mi.Ks),
HitPoint = ray.Point(rh.Distance),
TexCoord = texCoord,
FromDirection = -ray.Dir,
GeoNormal = ng,
ShadingNormal = ns,
FromLight = fromLight
};
//}
//else
//{
// HitPoint.HitPoint = ray.Point(rh.Distance);
// HitPoint.TexCoord = texCoord;
// HitPoint.FromDirection = -ray.Dir;
// HitPoint.GeoNormal = ng;
// HitPoint.ShadingNormal = ns;
// HitPoint.FromLight = fromLight;
//};
this.MaterialInfo = mi;
this.TexData = texData;
if (Frame == null)
this.Frame = new ONB(ref HitPoint.GeoNormal);
else
Frame.SetFromZ(ref HitPoint.GeoNormal);
}
protected override RgbSpectrum Sample(ref HitPointInfo HitPoint, ref Vector localFixedDir, out Vector localSampledDir, float u0, float u1, out float pdfW, out float absCosDir, out BsdfEvent _event)
{
var kr = (RgbSpectrum)TexData.Gloss + 0.5f;
var kt = (RgbSpectrum)(TexData.Transmittance??TexData.Diffuse) + 0.5f;
bool isKtBlack = kt.IsBlack();
bool isKrBlack = kr.IsBlack();
_event = BsdfEvent.None;
pdfW = 0f;
absCosDir = 0f;
localSampledDir = new Vector();
if (isKtBlack && isKrBlack)
return RgbSpectrum.ZeroSpectrum();
bool entering = (CosTheta(ref localFixedDir) > 0f);
float nc = TexData.PreviousMedium.IoR;
float nt = TexData.Medium.IoR;
float ntc = nt / nc;
float eta = entering ? (nc / nt) : ntc;
float costheta = CosTheta(ref localFixedDir);
// Decide to transmit or reflect
float threshold = isKrBlack ? 1f : (isKtBlack ? 0f : .5f);
RgbSpectrum result;
if (TexData.Event < threshold)
{
// Transmit
// Compute transmitted ray direction
float sini2 = SinTheta2(ref localFixedDir);
float eta2 = eta * eta;
float sint2 = eta2 * sini2;
// Handle total internal reflection for transmission
if (sint2 >= 1f)
return RgbSpectrum.ZeroSpectrum();
float cost = MathLab.Sqrt(Math.Max(0f, 1f - sint2)) * (entering ? -1f : 1f);
localSampledDir = new Vector(-eta * localFixedDir.x, -eta * localFixedDir.y, cost);
absCosDir = Math.Abs(CosTheta(ref localSampledDir));
_event = BsdfEvent.Specular | BsdfEvent.Transmit;
pdfW = threshold;
if (!HitPoint.FromLight)
result = (RgbSpectrum.UnitSpectrum() - FresnelCauchy_Evaluate(ntc, cost)) * eta2;
else
result = (RgbSpectrum.UnitSpectrum() - FresnelCauchy_Evaluate(ntc, costheta));
result *= kt;
}
else
{
// Reflect
localSampledDir = new Vector(-localFixedDir.x, -localFixedDir.y, localFixedDir.z);
absCosDir = Math.Abs(CosTheta(ref localSampledDir));
_event = BsdfEvent.Specular | BsdfEvent.Reflect;
pdfW = 1f - threshold;
result = kr * FresnelCauchy_Evaluate(ntc, costheta);
}
// The absCosSampledDir is used to compensate the other one used inside the integrator
return result / (absCosDir);
}
protected abstract RgbSpectrumInfo Evaluate(ref HitPointInfo HitPoint, ref Vector localLightDir,
ref Vector localEyeDir, out BsdfEvent _event, out float directPdfW, out float reversePdfW);
protected abstract RgbSpectrum Sample(ref HitPointInfo HitPoint, ref Vector localFixedDir,
out Vector localSampledDir, float u0, float u1, out float pdfW, out float absCosDir, out BsdfEvent _event);
