Does MeshLib supports vertex reordering

[ParvGuptaSpCT]

Hello Devs,

Does MeshLib supports reordering of mesh vertices

I'm looking for something like

Thanks

[Grantim]

Hello!

There are pack functions in Mesh class that are used to reorder vertices faces and edges:

MeshLib/source/MRMesh/MRMesh.h

Lines 418 to 425 in e085fff

	/// tightly packs all arrays eliminating lone edges and invalid face, verts and points,
	/// optionally returns mappings: old.id -> new.id
	MRMESH_API void pack( FaceMap * outFmap = nullptr, VertMap * outVmap = nullptr, WholeEdgeMap * outEmap = nullptr, bool rearrangeTriangles = false );
	/// packs tightly and rearranges vertices, triangles and edges to put close in space elements in close indices
	/// \param preserveAABBTree whether to keep valid mesh's AABB tree after return (it will take longer to compute and it will occupy more memory)
	MRMESH_API PackMapping packOptimally( bool preserveAABBTree = true );
	MRMESH_API Expected<PackMapping> packOptimally( bool preserveAABBTree, ProgressCallback cb );

Will it work for you?

[ParvGuptaSpCT]

Hello @Grantim,
Thanks for the quick reply, I tried implementing it
packMapping = mesh.packOptimally(True)
mesh.topology.pack(packMapping)
and get this result

My aim is to generate result like this

I also stubbled upon the Reorder class can it help?

Thanks

[Fedr]

Hello,

Now in MeshLib we have two options:

1. automatically reorder triangles and other elements to achieve maximal space locality: close in space elements will tend to have close indices in the mesh (and the result you showed above),
2. take user-provided mappings from old indices into new indices and apply it:

/// tightly packs all arrays eliminating lone edges and invalid faces, vertices and points,
/// reorder all faces, vertices and edges according to given maps, each containing old id -> new id mapping
Expected<void> Mesh::pack( const PackMapping & map, ProgressCallback cb = {} );

If you would like MeshLib to implement some specific reordering inside, please provide us with more information and links.