A computer-implemented process for displaying, on a graphical user interface of a CAD system, three-dimensional modeled objects of a database, the database comprising product structure definitions, the products being a hierarchy of three-dimensional modeled objects, comprising: - providing a database containing three-dimensional modeled objects; - providing the graphical user interface; - identifying a viewpoint on a three dimensional view of objects (21 - 24) to be rendered; and - rendering (S210 - 270) said three dimensional view according to the viewpoint, wherein the step of rendering comprises: - determining a plurality of locations (32a - i) in the three dimensional view, the locations being determined from a grid (32a - i) defined in the view; - searching the database and identifying therein modeled objects (21 - 24) according to the determined locations, the searching of the database and the identifying of the modeled objects comprising: - computing a ray passing through the viewpoint and at least one of the locations (32a - i) defined; - identifying one or more bounding volume (21b, 22b, 23b, 24b) of a respective modeled object (21, 22, 23, 24) intersecting the computed ray, the identifying of the one or more intersecting bounding volume being carried out recursively, based on is-composed-of relations stored in the database between the respective objects; and - identifying, amongst the objects corresponding to intersecting bounding volumes, the object the closest to the viewpoint; - establishing a ranking of the objects (21 - 24) identified in the database, the ranking being established by counting a number corresponding to one or more correspondences between the locations and an identified object; and - incrementally displaying (S220 - S270) according to said ranking, in the graphical user interface, the modeled objects (21 - 24) identified so as to rendering said three dimensional view. - providing a database containing three-dimensional modeled objects; - providing the graphical user interface; - identifying a viewpoint on a three dimensional view of objects (21 - 24) to be rendered; and - rendering (S210 - 270) said three dimensional view according to the viewpoint, wherein the step of rendering comprises: - determining a plurality of locations (32a - i) in the three dimensional view, the locations being determined from a grid (32a - i) defined in the view; - searching the database and identifying therein modeled objects (21 - 24) according to the determined locations, the searching of the database and the identifying of the modeled objects comprising: - computing a ray passing through the viewpoint and at least one of the locations (32a - i) defined; - identifying one or more bounding volume (21b, 22b, 23b, 24b) of a respective modeled object (21, 22, 23, 24) intersecting the computed ray, the identifying of the one or more intersecting bounding volume being carried out recursively, based on is-composed-of relations stored in the database between the respective objects; and - identifying, amongst the objects corresponding to intersecting bounding volumes, the object the closest to the viewpoint; - establishing a ranking of the objects (21 - 24) identified in the database, the ranking being established by counting a number corresponding to one or more correspondences between the locations and an identified object; and - incrementally displaying (S220 - S270) according to said ranking, in the graphical user interface, the modeled objects (21 - 24) identified so as to rendering said three dimensional view. - determining a plurality of locations (32a - i) in the three dimensional view, the locations being determined from a grid (32a - i) defined in the view; - searching the database and identifying therein modeled objects (21 - 24) according to the determined locations, the searching of the database and the identifying of the modeled objects comprising: - computing a ray passing through the viewpoint and at least one of the locations (32a - i) defined; - identifying one or more bounding volume (21b, 22b, 23b, 24b) of a respective modeled object (21, 22, 23, 24) intersecting the computed ray, the identifying of the one or more intersecting bounding volume being carried out recursively, based on is-composed-of relations stored in the database between the respective objects; and - identifying, amongst the objects corresponding to intersecting bounding volumes, the object the closest to the viewpoint; - computing a ray passing through the viewpoint and at least one of the locations (32a - i) defined; - identifying one or more bounding volume (21b, 22b, 23b, 24b) of a respective modeled object (21, 22, 23, 24) intersecting the computed ray, the identifying of the one or more intersecting bounding volume being carried out recursively, based on is-composed-of relations stored in the database between the respective objects; and - identifying, amongst the objects corresponding to intersecting bounding volumes, the object the closest to the viewpoint; - establishing a ranking of the objects (21 - 24) identified in the database, the ranking being established by counting a number corresponding to one or more correspondences between the locations and an identified object; and - incrementally displaying (S220 - S270) according to said ranking, in the graphical user interface, the modeled objects (21 - 24) identified so as to rendering said three dimensional view.