spectralbrain.compute_bks

spectralbrain.compute_bks(decomp)

Biharmonic Kernel Signature — parameter-free per-vertex scalar.

Uses the biharmonic operator (Δ²) instead of the heat operator. Unlike HKS and WKS, BKS has no tuneable parameter — it is fully determined by the eigenpairs.

\[\text{BKS}(x) = \sum_{i=1}^{k} \frac{\varphi_i^2(x)}{\lambda_i^2}\]

The 1/λ² weighting gives dominant weight to low-frequency modes (global shape).

Parameters:

decomp (SpectralDecomposition)

Returns:

ndarray, shape (N,) – Per-vertex BKS scalar.

Return type:

ndarray[tuple[Any, …], dtype[floating]]

References

Lipman Y, Rustamov RM, Funkhouser TA. Biharmonic distance. ACM Transactions on Graphics 29(3):27, 2010.