To create an eccentric (oblique) cone or cone frustum with an elliptic base, on the Geometry toolbar, from the More Primitives () menu, select Eccentric Cone (). You can also right-click the Geometry node to add this node from the context menu. Then enter the properties of the eccentric cone using the following sections:

From the Type list, select Solid or Surface to specify if the eccentric cone is a solid object or a (hollow) surface object.

Define the size and shape of the eccentric cone in the a-semiaxis, b-semiaxis, Height, Ratio, Top displacement 1, and Top displacement 2 fields. The bottom of the cone is an ellipse with semiaxes given in the a-semiaxis and b-semiaxis fields. The Height field determines the height of the cone frustum. The Ratio field controls the ratio between the perimeters of the top and bottom ellipses. To get an oblique cone, use the Top displacement fields to specify the displacement of the top ellipse’s center relative to the bottom ellipse’s center, in the cone’s local coordinate system.

Enter the position of the eccentric cone using the x, y, and z fields. This is the center of the bottom ellipse.

Specify the direction of the third axis of the cone’s local coordinate system — that is, the normal to the base ellipse. From the Axis type list, choose x-axis, y-axis, or z-axis (the default) to obtain an axis aligned with the specified coordinate axis. Choose Cartesian to enter a direction vector using the x, y, and z fields. Choose Spherical to enter the direction using the angles theta (polar, zenith) and phi (azimuth).

Specify the rotational angle about the axis in the Rotation field. When this angle is zero (the default), the second axis of the cone’s local coordinate system is parallel to the xy-plane.

The coordinate system in which the position, axis, and rotation angles above are interpreted. From the Work plane list, select xy-plane (the default, for a standard global Cartesian coordinate system) or select any work plane defined above this node in the geometry sequence. If you choose a work plane, the work plane and its coordinate system appear in the Graphics window, using an extra coordinate triad with the directions xw, yw, and zw (which are the used to specify the cone’s position).

If you want to make the resulting entities contribute to a cumulative selection, select a cumulative selection from the Contribute to list (the default, None, gives no contribution), or click the New button to create a new cumulative selection (see Cumulative Selections).

Select the Resulting objects selection check box to create predefined selections (for all levels — objects, domains, boundaries, edges, and points — that are applicable) in subsequent nodes in the geometry sequence. To also make all or one of the types of resulting entities (domains, boundaries, edges, and points) that the eccentric cone consists of available as selections in all applicable selection lists (in physics and materials settings, for example), choose an option from the Show in physics (Show in instances if in a geometry part) list: All levels, Domain selection, Boundary selection, Edge selection, or Point selection. The default is Domain selection, which is suitable for use with materials and physics defined in domains. For use with a boundary condition, for example, choose Boundary selection. These selections do not appear as separate selection nodes in the model tree. Select Off to not make any selection available outside of the geometry sequence.