Is it possible to create a buffer for a vector file in eCognition?! YES & EASY! There is an algorithm that takes over this job called "vector buffering". This algorithm will create a buffer around your thematic layer in a distance that you define. It works on polygons, lines and also on points!

A typical use case is creating samples from point vector data, and you have the option to choose between Miter, Round, and Square buffering.

Enjoy buffering!