The Ellipsoid primitive provides the user with a simple method for creating ellipses or "pills". There are many parameters available to the user to create variations on the default ellipse. By dragging in the 3D viewport with the tool active you can create the initial plane for the primitive. Once the initial plane is created, clicking away from one of the handles will snap that handle to the mouse position so that you can add dimension to the shape, or simply change the current values. If you wish to drag out a 3D ellipse, hold the CTRL key while dragging in the 3D view.
Ellipsoid--
Position X,Y,Z: These three values establish the 3D location for the center of the primitive.
Size X,Y,Z: These three values are used to establish the dimensions of the ellipsoid. The default values are 50cm, 50cm, 50cm
Sides: The sides are the latitudinal edges of the ellipsoid running from top to bottom. By default the primitive ellipsoid uses 24 sides. By increasing this value you can increase the number of "cuts" in the shape. This is useful if you plan to deform the ellipsoid as these segments act as "hinges" during deformation operations. This also increases the smoothness of the shape by adding extra facets.
Segments: The segments are the longitudinal edges of the ellipsoid running from right to left. By default the primitive uses 12 segments. By increasing this value you can increase the number of "cuts" in the primitive. This is useful if you plan to deform the shape as these segments act as "hinges" during deformation operations. It also increases the smoothness of the shape by adding extra facets.
Polygon Type: Users can use this option to determine the type of polygons created-
Face- Creates standard unsmoothed polygon faces.
Subdivs- Creates Subdivision Surface smoothed polygons.
Catmull-Clark-
Creates Pixar Catmull-Clark smoothed polygons.
Bulge Top: Increasing this value will change the shape from an elongated sphere to a rounded capped cylinder.
Side: Increasing this value will push the edges to the corners of the shape converting it into a flat sided ellipse.
Axis: This X,Y,Z choice allows you to quickly change the orientation of the primitive.
Make UVs: When this button is active a UV map will be automatically generated for the geometry created with the tool. This is a very useful option if you plan to UV map the model you are creating from the primitive as it provides a baseline UV map that you can massage later in the modeling process. In many cases this can reduce the amount of work required to map the model.
Min XYZ/Max XYZ: Users may also define the shape based on specific X, Y and Z bounding box locations in 3D space which can be specified here. This makes it easy to place a ellipsoid on the ground plane for instance by making the 'Min Y' value '0' and the 'Max Y' value '1m'.
TIP: The Ellipsoid primitive supports symmetrical creation. When Symmetry is activated, creating the primitive shape will create an identical version across the specified axis.
