zeux

Algorithms used for Cone* preprocess the mesh in some way, then split sequentially into 64-triangle clusters:
ConeBase: optimize mesh for transform cache
ConeSort: split mesh into large planar connected clusters, bin clusters into 6 buckets by cardinal axes, optimize each bucket for transform cache
ConeAcmr: optimize mesh for transform cache, split sequentially into variable length clusters that are relatively planar, sort clusters by avg normal
ConeCash: optimize mesh for transform cache, picking triangles that reduce ACMR but prioritizing those that keep current cluster planar
MaskBase: split sequentially into 64-triangle clusters, store a 64-bit conservative triangle mask for 6 frustums (cube faces)
ManyConeN: split sequentially into 64-triangle clusters, store N (up to 4) cones for each cluster and a cone id per triangle (2 bit)

Note that all Cone* solutions get significantly worse results with 128 or 256 triangle clusters; it doesn't matter much for Mask.
The biggest challenge with Cone* algorithms is t