edgeMateIndex

edgeMateIndex: undefined | number[] | undefined

Optional index array for moving "across an edge" to an adjacent facet.

• This array:
  • completes the topology of the polyface.
  • has the same length as the other PolyfaceData index arrays.
  • is populated by buildEdgeMateIndices.
  • is used by IndexedPolyfaceWalker to traverse the polyface.
  • is invalid if the polyface topology is subsequently changed.
• Let k1 = edgeMateIndex[k] be defined. Then:
  • k1 is an index (an "edge index") into the PolyfaceData index arrays. (The same for k.)
  • k and k1 refer to the two oppositely oriented sides of an interior edge in the polyface.
  • pointIndex[k1] is the point at the opposite end of the edge that starts at pointIndex[k].
  • edgeMateIndex[k1] === k.
• If k1 is undefined, then there is no adjacent facet across the edge that starts at pointIndex[k], i.e. k refers to a boundary edge.

Defined in

• polyface/PolyfaceData.ts Line 104