Function SGInnerProduct

BakingLab/SG.h:33–39

Computes the inner product of two SG's, which is equal to Integrate(SGx(v) * SGy(v) * dv).

// Computes the inner product of two SG's, which is equal to Integrate(SGx(v) * SGy(v) * dv).
inline Float3 SGInnerProduct(const SG& x, const SG& y)
{
    float umLength = Float3::Length(x.Sharpness * x.Axis + y.Sharpness * y.Axis);
    Float3 expo = std::exp(umLength - x.Sharpness - y.Sharpness) * x.Amplitude * y.Amplitude;
    float other = 1.0f - std::exp(-2.0f * umLength);
    return (2.0f * Pi * expo * other) / umLength;
}

// Returns an approximation of the clamped cosine lobe represented as an SG
inline SG CosineLobeSG(Float3 direction)