Method for comparing first computer-aided 3D model with a second computer-aided 3D model

1. A computer-implemented method for comparing successively a first computer-aided 3D model with a second computer-aided 3D model, the first model being described by a first topology comprising vertices, edges and faces of the first model and the second model being described by a second topology comprising vertices, edges and faces of the second model, the method being executed by a scanning component, a vertex mapping component, an edge mapping component and a face mapping component, the method comprising:

scanning the first topology and the second topology;

deriving from the first topology a first topological map relating vertices, edges and faces of the first model and from the second topology a second topological map relating vertices, edges and faces of the second model;

determining by means of the topological maps all possible mappings between vertices of the first model and vertices of the second model to generate mapped vertices;

using the mapped vertices to identify all possible mappings between edges of the first model and edges of the second model to generate mapped edges;

using the mapped edges to identify all possible mappings between faces of the first model and faces of the second model to generate mapped faces; and

using the mapped vertices, edges and faces to linearly compare the first model and the second model for geometrical sameness.

2. The method according to claim 1 , further comprising the step of producing a map which relates all mapped faces, edges and vertices between the first and second models, the map being used by verifications routines.

3. The method according to claim 2 , further comprising the step of classifying each face, edge or vertex of the first model and/or of the second model as one of three conditions, namely as a difference, as a modification or as an equivalent.

4. The method according to claim 1 , wherein the possible mappings between the vertices of the first and the second models is performed by using coordinates as matching criteria.

5. The method according to claim 1 , further comprising as a subsequent iteration the step of repeating all preceding steps with the first and second models being reversed.

6. The method according to claim 5 , wherein in the subsequent iteration only elements are considered which remained unmapped in the preceding iteration.

7. The method according claim 1 , wherein vertices, edges and faces of the first and second models are represented by appropriate data structures, respectively, the respective data structures are further collected in corresponding look-up tables.

8. A non-transitory computer-readable medium with a computer program stored thereon, the computer program comprising a program code comprising the steps of:

scanning the first topology and the second topology;

deriving from the first topology a first topological map relating vertices, edges and faces of the first model and from the second topology a second topological map relating vertices, edges and faces of the second model;

determining by means of the topological maps all possible mappings between vertices of the first model and vertices of the second model to generate mapped vertices;

using the mapped vertices to identify all possible mappings between edges of the first model and edges of the second model to generate mapped edges;

using the mapped edges to identify all possible mappings between faces of the first model and faces of the second model to generate mapped faces; and

using the mapped vertices, edges and faces to linearly compare the first model and the second model for geometrical sameness.