LerpedSurfaceOptics.h

Go to the documentation of this file.

#pragma once
 
#include "Core/SurfaceBehavior/SurfaceOptics.h"
#include "Core/Texture/texture_fwd.h"
#include "Math/Color/Spectrum.h"
#include "Core/Texture/TSampler.h"
 
#include <Common/primitive_type.h>
 
#include <memory>
#include <vector>
 
namespace ph
{
 
class LerpedSurfaceOptics : public SurfaceOptics
{
public:
    LerpedSurfaceOptics(
        const std::shared_ptr<SurfaceOptics>& optics0, 
        const std::shared_ptr<SurfaceOptics>& optics1);
 
    LerpedSurfaceOptics(
        const std::shared_ptr<SurfaceOptics>& optics0,
        const std::shared_ptr<SurfaceOptics>& optics1,
        real ratio);
 
    LerpedSurfaceOptics(
        const std::shared_ptr<SurfaceOptics>& optics0, 
        const std::shared_ptr<SurfaceOptics>& optics1,
        const std::shared_ptr<TTexture<math::Spectrum>>& ratio);
 
    ESurfacePhenomenon getPhenomenonOf(SurfaceElemental elemental) const override;
 
    std::string toString() const override;
 
private:
    void calcBsdf(
        const BsdfQueryContext& ctx,
        const BsdfEvalInput&    in,
        BsdfEvalOutput&         out) const override;
 
    void genBsdfSample(
        const BsdfQueryContext& ctx,
        const BsdfSampleInput&  in,
        SampleFlow&             sampleFlow,
        BsdfSampleOutput&       out) const override;
 
    void calcBsdfPdf(
        const BsdfQueryContext& ctx,
        const BsdfPdfInput&     in,
        BsdfPdfOutput&          out) const override;
 
    static real probabilityOfPickingOptics0(const math::Spectrum& ratio);
 
    std::shared_ptr<SurfaceOptics>            m_optics0;
    std::shared_ptr<SurfaceOptics>            m_optics1;
    std::shared_ptr<TTexture<math::Spectrum>> m_ratio;
    TSampler<math::Spectrum>                  m_sampler;
    bool                                      m_containsDelta;
};
 
// In-header Implementations:
 
inline std::string LerpedSurfaceOptics::toString() const
{
    return 
        "Lerped Surface Optics, "
        "optics_0: " + m_optics0->toString() + 
        "optics_1: " + m_optics1->toString() + 
        ", " + SurfaceOptics::toString();
}
 
inline real LerpedSurfaceOptics::probabilityOfPickingOptics0(const math::Spectrum& ratio)
{
    // Depending on the purpose of rendering, favoring human visual system may be preferable,
    // e.g., using luminance. Currently we use the absolute sum just to be fair.
    const real weight0 = ratio.abs().sum();
    const real weight1 = ratio.complement().abs().sum();
    return math::clamp(weight0 / (weight0 + weight1), 0.0_r, 1.0_r);
}
 
}// end namespace ph