at there been the discussion yesterday - - @Soren Larsen - for getting a new german passport in Bangkok at the embassy you need in general a copy of the birth or the marriage certificate - this information is from staff at the passport counter (same information as on website).
TLDR : Answer Summary
To obtain a new German passport in Bangkok at the embassy, you generally need to provide a copy of your birth certificate or marriage certificate, as confirmed by the embassy staff.