The basis of hashing in Alembic is the murmur3 hash. I'd recommend it. http://en.wikipedia.org/wiki/MurmurHash
-ben On Wed, Aug 15, 2012 at 2:19 PM, Nicolas Burtnyk <[email protected]> wrote: > I've used hashes of the geometry data itself (vertex and polygon data) to > identify meshes, but this obviously doesn't work if you want the hash to > remain stable between edits of the mesh. If you want to know if 2 meshes > are identical with just different names though, it's extremely reliable > assuming you have a good hash function. > > -Nicolas > > > > On Wed, Aug 15, 2012 at 10:49 AM, Alan Fregtman <[email protected]> > wrote: >> >> I know, but normal artists will extract geo and do other things that would >> destroy any metadata I could put on the object itself. >> >> >> On Wed, Aug 15, 2012 at 1:42 PM, Matt Lind <[email protected]> >> wrote: >>> >>> You’re describing Asset Management. >>> >>> >>> >>> A solution is to put metadata on each mesh (ie: custom property or >>> userdata blob) with a unique ID and register the asset somewhere such as in >>> a database. If the mesh is renamed, it’s name will be irrelevant as you’ll >>> be tracking the ID in the custom property, not the mesh name. You can >>> quickly find the custom properties via FindObjects(). You can resolve >>> collisions of duplicates using the mesh name. >>> >>> >>> >>> Matt >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> From: [email protected] >>> [mailto:[email protected]] On Behalf Of Alan Fregtman >>> Sent: Wednesday, August 15, 2012 8:28 AM >>> To: XSI Mailing List >>> Subject: Anyone ever tried generating a unique hash based on topology? >>> >>> >>> >>> Hey guys, >>> >>> >>> >>> I'm trying to keep track of a few thousand meshes which are being renamed >>> between stages/departments and I was thinking it might be worth a shot to >>> generate a hash based on topology so that I could track them better. >>> >>> >>> >>> Has anyone tried this already? I got pretty close hashing a string of >>> component counts and bounding box values... In a section of 415 meshes there >>> were only 8 hash collisions. >>> >>> >>> >>> Any ideas what else I can consider to make the hashes more unique? Or an >>> alternate solution to tracking existing sets of meshes with same topology >>> but potentially inconsistent naming? >>> >>> >>> >>> Cheers, >>> >>> >>> >>> -- Alan >>> >>> >> >> > -- Best regards, Ben Houston Voice: 613-762-4113 Skype: ben.exocortex Twitter: @exocortexcom http://Exocortex.com - Passionate CG Software Professionals.
