An apparatus for implementation of a post-processing system, the apparatus comprising a processor and a memory storing executable instructions that, in response to execution by the processor, cause the apparatus to implement: a diagramming engine configured to render a finite element model of a structural product, the finite element model representing the structural product by a mesh of elements each of which possesses a set of nodal points associated with a nodal dataset in which each nodal point is connected by an edge to each adjacent nodal point, and in which the nodal dataset for each set of nodal points includes values of a property or state of the structural product at respective nodal points of the set of nodal points; a string generator configured to generate a dynamically adjustable user-defined string defining an intersection of a slice plane with edges of the elements of the mesh across at least a portion of the mesh, wherein the string is or includes an interactive query that is formed where a slice plane intersects the numerical model such that the string intersects the edges of at least some of the elements of the mesh; an interpolator configured to create a set of intermediate points that coincide with intersection of the string and edges of at least some of the elements of the mesh, and calculate an interpolated dataset with which the set of intermediate points is associated, the interpolated dataset being calculated from the nodal dataset of the set of nodal points possessed by each element of the at least some of the elements; and a graphing engine configured to generate a plot of the interpolated dataset, wherein the string is dynamically adjustable such that in response to adjustment of the string, the string generator is configured to generate a corresponding adjusted string, and the interpolator is configured to create a new set of intermediate points that coincide with intersection of the adjusted string and edges of at least some of the elements of the mesh, and calculate an interpolated dataset with which the new set of intermediate points is associated. a diagramming engine configured to render a finite element model of a structural product, the finite element model representing the structural product by a mesh of elements each of which possesses a set of nodal points associated with a nodal dataset in which each nodal point is connected by an edge to each adjacent nodal point, and in which the nodal dataset for each set of nodal points includes values of a property or state of the structural product at respective nodal points of the set of nodal points; a string generator configured to generate a dynamically adjustable user-defined string defining an intersection of a slice plane with edges of the elements of the mesh across at least a portion of the mesh, wherein the string is or includes an interactive query that is formed where a slice plane intersects the numerical model such that the string intersects the edges of at least some of the elements of the mesh; an interpolator configured to create a set of intermediate points that coincide with intersection of the string and edges of at least some of the elements of the mesh, and calculate an interpolated dataset with which the set of intermediate points is associated, the interpolated dataset being calculated from the nodal dataset of the set of nodal points possessed by each element of the at least some of the elements; and a graphing engine configured to generate a plot of the interpolated dataset, wherein the string is dynamically adjustable such that in response to adjustment of the string, the string generator is configured to generate a corresponding adjusted string, and the interpolator is configured to create a new set of intermediate points that coincide with intersection of the adjusted string and edges of at least some of the elements of the mesh, and calculate an interpolated dataset with which the new set of intermediate points is associated.