The Sphere source can be used
to add a polygonal sphere to the 3D scene. The center and radius of the
sphere, the resolution of the polygonal approximation, and starting /
ending angles can be changed used the property sheet. The sphere can be
translated,
rotated, and scaled using the Actor control area of the Display tab for
this source, and it can be interactively positioned using the Move operation
of the camera. The
object created by this source is a vtkSphereSource
object, and the output of this source is vtkPolyData.
The output polydata has point normals defined. An example of a sphere
source is given on the right. For this example, the resolutions were changed
to 200, the End Theta angle was set to 320, the End Phi angle was set
to 120, and the sphere is colored by Point Normals 1.
The Sphere source has the following parameters:
Center:
This coordinate represents the center of the sphere. By default this value
is (0,0,0).
Radius:
This is the radius of the sphere. The default value is 0.5.
Theta
Resolution: This number represents the number of division between
start theta and end theta around the sphere. The theta divisions are similar
to longitude lines on the earth. The higher the resolution the closer
the approximation will come to a sphere and the more polygons there will
be. The default theta resolution is 8.
Start
Theta: To form a complete sphere the start theta should be 0 and
the end theta should be 360. The start theta can be adjusted to form only
a portion of a sphere. The default value is 0.
End
Theta: The end theta can be adjusted to form only a portion of
a sphere as shown in the example above. The default end theta value is
360.
Phi
Resolution: This number represents the number of division between
start phi and end phi on the sphere. The phi divisions are similar to
latitude lines on the earth. The default phi resolution is 8.
Start
Phi: To form a complete sphere the start phi should be 0 and the
end phi should be 180. The start phi can be adjusted to form only a portion
of a sphere. The default value is 0.
End
Phi: The end phi value can be adjusted to form only a portion of
a sphere. In the example above both the end theta end phi values were
reduced to leave a gap in the sphere both in the longitudinal and latitudinal
directions.
The Sphere source can be used
to add a polygonal sphere to the 3D scene. The center and radius of the
sphere, the resolution of the polygonal approximation, and starting /
ending angles can be changed used the property sheet. The sphere can be
translated,
rotated, and scaled using the Actor control area of the Display tab for
this source, and it can be interactively positioned using the Move operation
of the camera. The
object created by this source is a vtkSphereSource
object, and the output of this source is vtkPolyData.
The output polydata has point normals defined. An example of a sphere
source is given on the right. For this example, the resolutions were changed
to 200, the End Theta angle was set to 320, the End Phi angle was set
to 120, and the sphere is colored by Point Normals 1.