Skip to main content
Version: 4.x

Vertex mode

An H3 Vertex index (mode 4) represents a single topological vertex in H3 grid system, shared by three cells. Note that this does not include the distortion vertexes occasionally present in a cell's geographic boundary. An H3 Vertex is arbitrarily assigned one of the three neighboring cells as its "owner", which is used to calculate the canonical index and geographic coordinates for the vertex. The components of the H3 Vertex index are packed into a 64-bit integer in order, highest bit first, as follows:

  • 1 bit reserved and set to 0,
  • 4 bits to indicate the H3 Vertex index mode,
  • 3 bits to indicate the vertex number (0-5) of vertex on the owner cell,
  • Subsequent bits matching the index bits of the owner cell.

Bit layout of H3Index for vertexes

The layout of an H3Index for vertexes is shown below in table form. The interpretation of the "Mode-Dependent" field differs depending on the mode of the index.

0x30Reserved (0)Mode (4)VertexResolutionBase cell
0x20Base cellDigit 1Digit 2Digit 3Digit 4Digit 5
0x10Digit 5Digit 6Digit 7Digit 8Digit 9Digit 10
0x00Digit 10Digit 11Digit 12Digit 13Digit 14Digit 15