Abstract: A method for processing a shape attribute 3D signal including providing a graph having nodes and arcs, each node representing a point of a 3D discrete representation, each arc representing neighboring points of the representation, providing a set of values representing a distribution of the shape attribute, each value being associated to a node and representing the shape attribute at the point represented by the node, minimizing energy on a Markov Random Field on the graph, the energy penalizing, for each arc connecting a first node associated to a first value to a second node associated to a second value, highness of an increasing function of a distance between the first and second value, a distance between a first point, represented by the first node, and a medial geometrical element of the representation, and a distance between a second point, represented by the second node, and the medial geometrical element.

Abstract: The disclosure notably relates to a computer-implemented method for generating a structured three-dimensional (3D) model from a mesh. The method includes obtaining a mesh that comprises faces, each face of the mesh including a normal and principal curvature values; computing a distribution of the principal curvatures values over the whole mesh by counting the number of occurrences of discretized curvature values; identifying in the computed distribution one or more dominant ranges of principal curvature values; for each identified dominant range, computing one or more regions of the mesh that includes faces belonging to the identified dominant range; for each computed region, detecting a primitive type by using the curvatures values of all faces of the region and identifying parameters of the detected primitive by using the mesh surface of the region.

Abstract: The disclosure notably relates to a computer-implemented method for extracting a feature tree from a mesh. The method includes providing a mesh, computing a geometric and adjacency graph of the provided mesh, wherein each node of the graph represents one region of the mesh and comprises a primitive type and parameters of the region, each connection between two nodes is an intersection between the respective surfaces of the regions represented by the two connected nodes. The method also includes instantiating for each node of the graph, a surface based on the identified primitive type and parameters of the region.

Abstract: A method for processing a shape attribute 3D signal including providing a graph having nodes and arcs, each node representing a point of a 3D discrete representation, each arc representing neighboring points of the representation, providing a set of values representing a distribution of the shape attribute, each value being associated to a node and representing the shape attribute at the point represented by the node, minimizing energy on a Markov Random Field on the graph, the energy penalizing, for each arc connecting a first node associated to a first value to a second node associated to a second value, highness of an increasing function of a distance between the first and second value, a distance between a first point, represented by the first node, and a medial geometrical element of the representation, and a distance between a second point, represented by the second node, and the medial geometrical element.

Abstract: The disclosure notably relates to a computer-implemented method for 3D reconstruction. The method comprises providing a 3D point cloud representing a real object. The method also comprises fitting the 3D point cloud with parametric surfaces. The method also comprises defining a partition of the parametric surfaces into oriented facets which respect intersections between the parametric surfaces. The method also comprises determining, among the oriented facets of the partition, a set of facets that represents a skin of the real object. The determining comprises minimizing an energy. The energy includes a data term and a constraint term. The data term increasingly penalizes discarding facets, as a level of fit between a discarded facet and the 3D point cloud increases. The constraint term penalizes formation of non-skin geometry by kept facets. Such a method provides an improved solution for 3D reconstruction.

Abstract: The disclosure notably relates to a computer-implemented method for extracting a feature tree from a mesh. The method includes providing a mesh, computing a geometric and adjacency graph of the provided mesh, wherein each node of the graph represents one region of the mesh and comprises a primitive type and parameters of the region, each connection between two nodes is an intersection between the respective surfaces of the regions represented by the two connected nodes. The method also includes instantiating for each node of the graph, a surface based on the identified primitive type and parameters of the region.

Abstract: The disclosure notably relates to a computer-implemented method for generating a structured three-dimensional (3D) model from a mesh. The method includes obtaining a mesh that comprises faces, each face of the mesh including a normal and principal curvature values; computing a distribution of the principal curvatures values over the whole mesh by counting the number of occurrences of discretized curvature values; identifying in the computed distribution one or more dominant ranges of principal curvature values; for each identified dominant range, computing one or more regions of the mesh that includes faces belonging to the identified dominant range; for each computed region, detecting a primitive type by using the curvatures values of all faces of the region and identifying parameters of the detected primitive by using the mesh surface of the region.

Abstract: The disclosure notably relates to a computer-implemented method for 3D reconstruction. The method comprises providing a 3D point cloud representing a real object. The method also comprises fitting the 3D point cloud with parametric surfaces. The method also comprises defining a partition of the parametric surfaces into oriented facets which respect intersections between the parametric surfaces. The method also comprises determining, among the oriented facets of the partition, a set of facets that represents a skin of the real object. The determining comprises minimizing an energy. The energy includes a data term and a constraint term. The data term increasingly penalizes discarding facets, as a level of fit between a discarded facet and the 3D point cloud increases. The constraint term penalizes formation of non-skin geometry by kept facets. Such a method provides an improved solution for 3D reconstruction.