|
Action:
|
Evaluates the principal axes of curvature and corresponding curvatures of a three-dimensional B-spline surface at a given
uv.
|
|
|
Prototype:
|
void bs3_surface_prin_curv (
|
|
|
SPApar_pos const& uv,
|
// given parameter point
|
|
|
bs3_surface bs,
|
// given surface
|
|
|
SPAunit_vector& u1,
|
// returned first
|
|
|
|
|
// principal axis
|
|
|
double& c1,
|
// returned first
|
|
|
|
|
// curvature
|
|
|
SPAunit_vector& u2,
|
// returned second
|
|
|
|
|
// principal axis
|
|
|
double& c2
|
// returned second
|
|
|
|
|
// curvature
|
|
|
);
|
|
|
Includes:
|
#include "kernel/acis.hxx"
|
|
#include "baseutil/vector/param.hxx"
|
|
#include "baseutil/vector/unitvec.hxx"
|
|
#include "kernel/spline/bs3_srf/bs3surf.hxx"
|
|
#include "kernel/spline/bs3_srf/sp3srtn.hxx"
|
|
|
Description:
|
The sign and order of the principal axes, are not significant. The sign of the curvature value indicates whether the surface is convex or concave with respect to the normal direction, which is considered to point out from the region bounded by the surface. A convex surface (one that curves back from the outward normal direction) has positive curvature, a concave one has negative curvature.
|
|
|
Errors:
|
Returns without setting anything if the input surface is null.
|
|
|
Library:
|
kernel
|
|
|
Filename:
|
kern/kernel/spline/bs3_srf/sp3srtn.hxx
|
|
|
Effect:
|
Read-only
|