A method for B-Rep face and edge connectivity compression in a data processing system for managing 3D data, the method comprising the steps: receiving, in the data processing system, B-Rep data of a graphic model (405, 505), the B-Rep data including a plurality of edges (e) and coedges (c) wherein each edge (e) has at least one corresponding coedge (c); constructing, from the B-Rep data and by the data processing system, a vertex table having coordinates of a plurality of vertices (v) of the graphic model (405, 505); constructing, from the B-Rep data and by the data processing system, an edge table associating each edge (e) of the graphic model (405, 505) with at least one of the plurality of vertices (v) of the graphic model (405, 505); traversing (740, 765, 635), by the data processing system, from a first edge (e) to a corresponding first coedge (c), from the first coedge (c) to a second coedge (c) that is in a coedge loop with the first coedge (c), and from the second coedge (c) to a corresponding second edge (e), to identify a common vertex (v) between the first edge (e) and the second edge (e) so as to obtain face and edge connectivity information; representing said face connectivity information by edge index references in each coedge, wherein when the coedges are visited sequentially, indexing the corresponding edges by: - for each coedge that references an edge which has not been referenced yet, storing an invalid index while inferring the actual edge index by keeping track of the count of invalid indices when looping through the coedge array; and - for each coedge that references and edge that has already been referenced, storing the actual edge index; - compressing said face connectivity information by using an entropy encoder. receiving, in the data processing system, B-Rep data of a graphic model (405, 505), the B-Rep data including a plurality of edges (e) and coedges (c) wherein each edge (e) has at least one corresponding coedge (c); constructing, from the B-Rep data and by the data processing system, a vertex table having coordinates of a plurality of vertices (v) of the graphic model (405, 505); constructing, from the B-Rep data and by the data processing system, an edge table associating each edge (e) of the graphic model (405, 505) with at least one of the plurality of vertices (v) of the graphic model (405, 505); traversing (740, 765, 635), by the data processing system, from a first edge (e) to a corresponding first coedge (c), from the first coedge (c) to a second coedge (c) that is in a coedge loop with the first coedge (c), and from the second coedge (c) to a corresponding second edge (e), to identify a common vertex (v) between the first edge (e) and the second edge (e) so as to obtain face and edge connectivity information; representing said face connectivity information by edge index references in each coedge, wherein when the coedges are visited sequentially, indexing the corresponding edges by: - for each coedge that references an edge which has not been referenced yet, storing an invalid index while inferring the actual edge index by keeping track of the count of invalid indices when looping through the coedge array; and - for each coedge that references and edge that has already been referenced, storing the actual edge index; - compressing said face connectivity information by using an entropy encoder. - for each coedge that references an edge which has not been referenced yet, storing an invalid index while inferring the actual edge index by keeping track of the count of invalid indices when looping through the coedge array; and - for each coedge that references and edge that has already been referenced, storing the actual edge index; - compressing said face connectivity information by using an entropy encoder.