What does packMesh mean?

[Gihong-Yim]

RemeshSettings settings;
settings.targetEdgeLen = dEdgeLength;
settings.maxEdgeSplits = 100000;
settings.packMesh = true;
Even after reading the explanation, I still don’t fully understand the meaning of the packMesh variable. Could you clarify its purpose?

[Grantim]

Hello!

Remesh algorithms applies decimation and subdivision:

1. decimation collapses too long edges witch means that some vertices and faces are removed from mesh, and other replaced
2. subdivision introduce new vertices and faces

For example mesh had 5 faces:
face_0,face_1,face_2,face_3.face_4
we removed face_1 and face_3, so we still have array of 5 face, but 2 are removed:
face_0,_,face_2,_.face_4
the mesh still takes same amount of memory.

So here pack arrives, it deallocate not used space in Faces, Vertices and Edges arrays making them "dense",
in this case pack do this
face_0->new_face_0
face_2->new_face_1
face_4->new_face_2
and result mesh looks like this:
new_face_0,new_face_1,new_face_2,

please note that it is simple example and really pack can reorder arrays too