# Synopsis

PDX_MSGT gcr_Sphere(long option, MDA_PTR orig_db_ptr, MTH_3DPNT center, MTH_3DVEC axis_vec, MTH_3DVEC ref_vec, double radius, int gdx_model, MDA_PTR *gdx_sphere_ptr)

# Purpose

Create a GDX Sphere.

# Description

Given a point on the sphere axis, a sphere axis vector, the radius of the sphere, and the U parametrization reference vector, create a GDX sphere entity.

The radius must be > the current GDX ZERO_TOL.

If ref_vec is not NULL, the corresponding magnitude of the given vector must be > the current GDX NORMAL_MAG_TOL. If the given vector is not perpendicular to the sphere axis vector within the current GDX ANGLE_TOL, the closest perpendicular vector is used.

If the ref_vec is NULL, an arbitrary ref_vec (perpendicular to the given axis_vec) will be determined and stored in the entity.

If the magnitude of the axis_vec sphere axis vector is less than the current GDX NORMAL_MAG_TOL, the Z sphere axis vector is assumed.

\fBRules\fR .IP • 3 radius > 0.0 .IP • 3 ref_vec magnitude > 0.0 (if ref_vec not NULL) .LP

# Input

## option

### GCR_NOVALIDATE

No validation will occur on the input data

## orig_db_ptr

The original entities orig_db_ptr as obtained from the mda_GetOrigDbptr function call, or MDA_NULL_PTR

## center

The sphere point

## axis_vec

The center axis of the sphere

## radius

The radius of the sphere at the sphere point

## ref_vec

The U parametric axis reference vector, or NULL

## gdx_model

The GDX model for entity creation

# Output

## gdx_sphere_ptr

Entity database pointer of the GDX Sphere

# Tolerances

          NORMAL_MAG_TOL
          ANGLE_TOL
          ZERO_TOL
          .fi

# Return

          GCR_NOERR
          GCR_SPHERE_RADIUS
          GCR_SPHERE_U_REF_VECTOR
          Low level error return
          .fi