Ellipsoids

An ellipsoid is a three-dimensional surface defined by an origin (that is, the center of the ellipsoid) and three mutually perpendicular vectors that define the orientation and the major and minor radii of the ellipsoid. An ellipsoid is defined by the TQ3EllipsoidData data type. See "Creating and Editing Ellipsoids" for a description of the routines you can use to create and edit ellipsoids. Figure 31 shows an ellipsoid.

Figure 31 An ellipsoid

typedef struct TQ3EllipsoidData {
    TQ3Point3D                          origin;
    TQ3Vector3D                         orientation;
    TQ3Vector3D                         majorRadius;
    TQ3Vector3D                         minorRadius;
    float                               uMin, uMax, vMin, vMax;
    TQ3EndCap                           caps;
    TQ3AttributeSet                     interiorAttributeSet;
    TQ3AttributeSet                     ellipsoidAttributeSet;
} TQ3EllipsoidData;


origin

The origin (that is, the center) of the ellipsoid.

orientation

The orientation of the ellipsoid.

majorRadius

The major radius of the ellipsoid.

minorRadius

The minor radius of the ellipsoid.

uMin

The minimum value in the u parametric direction of the ellipsoid. This value should be greater than or equal to 0.0 and less than or equal to 1.0.

uMax

The maximum value in the u parametric direction of the ellipsoid. This value should be greater than or equal to 0.0 and less than or equal to 1.0.

vMin

The minimum value in the v parametric direction of the ellipsoid. This value should be greater than or equal to 0.0 and less than or equal to 1.0.

vMax

The maximum value in the v parametric direction of the ellipsoid. This value should be greater than or equal to 0.0 and less than or equal to 1.0.

caps

The style of caps to be used on the ellipsoid ends. See "End Caps Masks" for a description of the masks you can use to specify a value for this field.

interiorAttributeSet

A set of ellipsoid interior attributes.

ellipsoidAttributeSet

A set of attributes for the ellipsoid. The value in this field is NULL if no ellipsoid attributes are defined.

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© 1997 Apple Computer, Inc.

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