Some confusing about convert_geometry() funciton of i3s_writer_impl.cpp.

In function `i3slib::i3s::convert_geomery()`, I notice that `src_pos` return a relative position of mesh, which should be a `std::vector`, and the `src_pos.size()` should return the size of vertices. But when I use a vertices with triangluar indices, the `size()` function of `Mesh_attrb` return an index size like this:
so, the next step code (in row 213)
will always touch an assert: ERROR: mesh->size() != rel_pos.size();
I want to know, did I miss something? or the indices should not calculate like this?

Start in i3s_writer_impl.cpp at convert_geometry() and inspect how src_pos, Mesh_attrb::size(), and triangular indices are populated before the assertion at row 213. Reproduce the reported mesh case and determine whether the conversion should compare vertex counts or index counts; done means the assertion behavior is explained and the issue’s expected handling is clear.

Written by the indexing model from the issue text.