Local Properties of Shapes

The Local Properties of Shapes component provides algorithms for computing various local properties on edges and faces in a BRep model.

The local properties which may be queried are:

- for a point of parameter u on a curve which supports an edge :

- the point,

- the derivative vectors, up to the third degree,

- the tangent vector,

- the normal,

- the curvature, and the center of curvature;

- for a point of parameter (u, v) on a surface which supports a face :

- the point,

- the derivative vectors, up to the second degree,

- the tangent vectors to the u and v isoparametric curves,

- the normal vector,

- the minimum or maximum curvature, and the corresponding directions of curvature;

- the degree of continuity of a curve which supports an edge, built by the concatenation of two other edges, at their junction point.

Analysed edges and faces are described as BRepAdaptor curves and surfaces, which provide shapes with an interface for the description of their geometric support. The base point for local properties is defined by its u parameter value on a curve, or its (u, v) parameter values on a surface.

The services of the "Local Properties of Shapes" component are provided by the package BRepLProp.

Note : The Local Properties of Curves and Surfaces component also provides these computations, but only on Geom curves and surfaces.