Abstract: Current mainstream commercial CAD software still has functional limitations that
can’t meet the requirements of manufacturing enterprises. To realize the annotation of parts,
especially parts with complex features, the rapid annotation of 3D model in CAD system is
investigated based on the standard GB/T 24734. A rapid 3D annotation algorithm is proposed, and
the relevant technology is illustrated in detail. The procedures of rapid annotation mainly deal with
the auto-construction of annotation plane, the computation of dimension elements, and the
processing of annotation results. The classification of annotation plane and the cursor point
transformation are introduced to automatically construct annotation plane. All the annotation results
are handled to display in a forward direction. All the algorithms presented are realized and the
verification is conducted on the CATIA V5 system. The results prove that the proposed 3D rapid
annotation algorithm performs well.

Key words: computer aided design, 3D dimension annotation, GB/T 24734, CATIA