Mapping between vertices of the original and offset polygon?

[jkavalik]

Hello, is there any way to find which input vertex is "responsible" for which output one?
I understand it is not a simple mapping function, sometimes multiple vertices collapse into one and rounded edges generate many vertices from one. I could probably do a search for closest ones, but that seems error-prone.

[mmassing]

Maybe you could repurpose the z coordinate to encode the source vertex index.

[jkavalik]

Makes sense, will test it. Thank you for the idea :)

[jkavalik]

Doing some experiments and it seems to mostly work as I would expect for convex edges - the newly generated vertices keep the "origin" Z value (round and other types but bevel, that one for some reason resets the Z value, using neither original nor the callback, but I am not interested in that one :) )
Will have to do some more testing on concave shapes - I will probably have to keep a separate list of "collapsed into" for the lost points, but the callback should handle that.
Thanks again.

[AngusJohnson]

USINGZ and offsetting with bevel join type was buggy and this has just been fixed in the latest repository revision.