public override IRadianceEvaluation Sample(ref Vector wo, ref IRadianceEvaluation radiance, float u0, float u1, float u2,
out BsdfSample result, BrdfType flags = BrdfType.All)
{
result = new BsdfSample()
{
};
throw new NotImplementedException();
}
public override void F(ShadePointInfo pt, out IColorType fs, BrdfType types = BrdfType.Diffuse)
{
float c = 1f - Vector.Dot(ref pt.IncomingDirection, ref pt.ShadingNormal);
float Re = R0 + (1f - R0) * c * c * c * c * c;
float P = .25f + .5f * Re;
fs = pt.Diffuse.CloneValue().Mul(MathLab.INVPI).Mul((1f - Re) / (1f - P));
}
public IRadianceEvaluation Sample(ref Vector wo, ref IRadianceEvaluation radiance, float u0, float u1, float u2, out BsdfSample result, BrdfType flags = BrdfType.All)
{
float selPdf;
BaseBsdf bxdf = GetBsdf(out selPdf, flags);
if (bxdf == null)
{
result = new BsdfSample();
return ColorManager.Instance.ZeroRadiance();
}
Vector wo1 = bxdf.WorldToLocal(ref wo);
var r = bxdf.Sample(ref wo1, ref radiance, u0, u1, u2, out result, flags);
result.DirectPdf *= selPdf;
result.OutgoingDirection = bxdf.LocalToWorld(ref result.OutgoingDirection);
return r;
/*Vector wi = new Vector();
var wiW = Vector.Zero;
var pdf = 0f;
bool specularBounce;
if (pdf > 0f && pdf < MathLab.Epsilon) return ColorManager.Instance.ZeroRadiance();
if (flags != BrdfType.All ) flags = bxdf.Type;
wiW = bxdf.LocalToWorld(ref wi);
if ((!bxdf.Type.Has(BrdfType.Specular)) && matchingComps > 1)
{
for (int i = 0; i < bxdfs.Count; ++i)
{
if (bxdfs[i] != bxdf &&bxdfs[i].Type.Has(flags))
pdf += bxdfs[i].Pdf(scene, ref wo);
}
}
if (matchingComps > 1) pdf /= matchingComps;
if (bxdf.Type.Has(BrdfType.Specular))
{
var f = ColorManager.Instance.ZeroRadiance();
if ((Vector.Dot(ref wiW , ref bxdf.Ng)) * Vector.Dot(ref wo1 ,ref bxdf.Ng) > 0f)
// ignore BTDFs
{
flags = flags & ~BrdfType.Refractive;
}
else
// ignore BRDFs
flags = flags & ~BrdfType.Reflection;
float cosp, rwp;
for (int i = 0; i < bxdfs.Count; ++i)
if (bxdfs[i].Type.Has(flags))
f.Add(bxdfs[i].Evaluate(scene, ref wo, Vector.Dot(ref wiW, ref bxdf.Ng), out cosp, out rwp));
f.Div(pdf);
}
return f;*/
}
public static bool Has(BrdfType val, BrdfType f)
{
//return val.HasFlag(f);
return ((uint)val & (uint)f).Equals((uint)f);
}
public void f(ref Vector lwo, ref Vector lwi, ref Normal N, ref RgbSpectrum in_fs, out RgbSpectrum fs, BrdfType types = BrdfType.Diffuse)
{
this.CreateFrame(ref N);
var wo = this.WorldToLocal(ref lwo);
var wi = this.WorldToLocal(ref lwi);
if (brdfs.Length == 1)
{
if (brdfs[0].IsSpecular())
{
fs = new RgbSpectrum(0f);
}
else
brdfs[0].f(ref wo, ref wi, ref N, out fs);
return;
}
var res = new RgbSpectrum();
fs = new RgbSpectrum();
foreach (var surfaceBsdf in brdfs)
{
if (surfaceBsdf.Type.HasFlag(types))
{
surfaceBsdf.f(ref wo, ref wi, ref N, out res);
fs += res;
}
}
}
public override void F(ShadePointInfo pt, out IColorType fs, BrdfType types = BrdfType.Diffuse)
{
throw new NotImplementedException();
}
public abstract void F(ShadePointInfo pt, out IColorType fs, BrdfType types = BrdfType.Diffuse);
private BaseBsdf GetBsdf(out float pdf, BrdfType flags = BrdfType.All)
{
int matchingComps = 0;
BaseBsdf b = null;
foreach (var baseBsdf in bxdfs)
{
if (BaseBsdf.Has(baseBsdf.Type, flags))
{
if (b == null)
b = baseBsdf;
matchingComps++;
}
}
pdf = 1f / matchingComps;
return b;
}
public void f(ref Vector wo, ref Vector wi, ref Normal N, ref RgbSpectrum in_fs, out RgbSpectrum fs, BrdfType types = BrdfType.Diffuse)
{
throw new NotImplementedException();
}
public override void F(ShadePointInfo pt, out IColorType fs, BrdfType types = BrdfType.Diffuse)
{
fs = pt.Diffuse.Mul(MathLab.INVPI);
}
public static bool Has(this BrdfType val, BrdfType f)
{
//return val.HasFlag(f);
return ((byte)val & (byte)f).Equals((byte)f);
}
