Class SoNurbsProperty

  • All Implemented Interfaces:

    public class SoNurbsProperty
    extends SoNode
    Node that defines additional properties for rendering a NURBS surface. This node defines an additional set of properties used by SoNurbsSurface when rendering NURBS surfaces.

    For a large NURBS surface, it is sometimes more effective to display two central isoparametric curves rather than facet boundaries (as in wireframe mode) because the latter may provide an overly complicated view of the surface.

    This node allows you to specify the NURBS draw style; the color of the trim curves, boundaries and isoparametric curves; the line pattern of the isoparametric curves; the number of sample points between trim curves control points; the type of tessellation; angle and distance for adaptive tessellation.

    The NURBS draw style is a bitmask specifying which combination of the following representations to use for displaying the NURBS: normal display, trim curves and boundaries, and/or central isoparametric curves.

    Turning off the normal NURBS surface display, and turning on the display of trim curves, boundaries and isoparametric curves can dramatically speed up rendering of large models.

    When in ADAPTIVE tessellation mode, regions with a low curvature will be less tessellated than regions with a high curvature.

    File format/default:

    NurbsProperty {

      drawStyle NORMAL
      numSamplePoints -1
      color 1 1 1
      isoParamCurvesPattern 0xFFFF
      tessellationType CONSTANT
      tessellationDistance 0.01
      tessellationAngle 0.35

    Action behavior:

    Sets: SoNurbsPropertyElement

    See Also:
    • Field Detail

      • numSamplePoints

        public final SoSFInt32 numSamplePoints
        numSamplePoints is used during trim curve tessellation. It specifies the exact number of points to generate between two trim curve control points. If set to -1 (the default), the number of points generated is computed from the SoComplexity node. Setting this field to a small value (less than 3) can reduce the number of triangles generated by the tessellation and thus increase the drawing performance of trimmed NURBS surfaces.
      • color

        public final SoSFColor color
        Contains the color used to render trim curves and isoparametric curves.
      • isoParamCurvesPattern

        public final SoSFUShort isoParamCurvesPattern
        Sets a specific line pattern for isoparametric curves.
    • tessellationDistance

      public final SoSFFloat tessellationDistance
      Used when tessellationType is set to ADAPTIVE. The maximum tessellation step size (curvilinear distance) is this fraction of the diagonal of the bounding box of the surface or the group of surfaces (SoNurbsGroup). Increasing this value make the tessellation more dependent on tessellationAngle. Default value is 0.01. That is, the distance must not be more than 1% of the diagonal of the bounding box.

      Open Inventor 6.0

    • tessellationAngle

      public final SoSFFloat tessellationAngle
      Used when tessellationType is set to ADAPTIVE. Specifies the maximum angle (in radians) between the normals of two adjacent tessellated faces. Decreasing this value adds more tessellation points on flat parts of the surface. Default value is 0.35

      Open Inventor 6.0

  • Constructor Detail

    • SoNurbsProperty

      public SoNurbsProperty()