HM_ExtAPI::SurfaceSphereGetData()
Returns parameters that define spherical surface.
Syntax
bool SurfaceSphereGetData(
const HM_EntityGeometrySurface & surface,
HM_Point& center,
HM_Vector& unit_north_pole,
HM_Vector& unit_origin_dir,
double& radius,
bool& reverse_u
);Type
HyperMesh Ext API
Description
The function expects that the type of surface object is HM_ExtAPI::SPHERE(). Application should call the function HM_ExtAPI::GeomSurfaceGetType() to verify the type before calling SurfaceSphereGetData function.
The points on the sphere surface can be calculated parametrically as
S(U, V) = C + R n sin V + R cos V ( p cos U + η [n X p ] sin U )
The following table summarizes correspondence of the parameters used in the equation to parameters returned by the function SurfaceSphereGetData.
| Parameters returned by SurfaceSphereGetData | Sphere parameters |
|---|---|
| center | C |
| unit_north_pole | n |
| unit_origin_dir | P |
| radius | R |
| reverse_u | If false then η = 1 If true then η = -1 |
If the function succeeds, the return value is true. If the function fails, the return value is false. To get extended value information, call HM_ExtAPI::GetLastErrorCode().
Requires including hm_extapi.h.
Inputs
- surface
- [in] - Handle to surface object that was returned by previous calls to API functions.
- center
- [out] - Sphere center point.
- unit_north_pole
- [out] - Unit length vector that defines direction from center point to sphere’s “north pole”.
- unit_origin_dir
- [out] - Unit length vector that defines direction from center point to sphere’s “equator” point with parameters U=0, V=0.
- radius
- [out] - Sphere radius.
- reverse_u
- [out] - Flag that defines direction of constant V parametric lines along the axis of the sphere. The value of false indicates counter clockwise direction of constant V parametric lines with respect to the “north pole” direction unit_north_pole. The value of true indicates clockwise direction of constant V parametric lines.
Errors
None.