gml:Bezier
Bezier curves are polynomial splines that use Bezier or Bernstein polynomials for interpolation purposes. It is a special case of the B-Spline curve with two knots. degree shall be the degree of the polynomial used for interpolation in this spline. knot shall be the sequence of distinct knots used to define the spline basis functions. interpolation is fixed as "polynomialSpline". isPolynomial is fixed as "true". knotType is not relevant for Bezier curve segments.
Element information
Namespace: http://www.opengis.net/gml/3.2
Schema document: external/ogc/gml/3.2.1/geometryPrimitives.xsd
Type: gml:BezierType
Properties: Global, Qualified
Content
- Sequence [1..1]
- Choice [1..1]
- Choice [0..*]
- gml:pos
- gml:pointProperty This property element either references a point via the XLink-attributes or contains the point element. pointProperty is the predefined property which may be used by GML Application Schemas whenever a GML feature has a property with a value that is substitutable for Point.
- gml:pointRep deprecated
- gml:posList
- gml:coordinates deprecated
- Choice [0..*]
- gml:degree [1..1]
- gml:knot [2..2]
- Choice [1..1]
Attributes
Name | Occ | Type | Description | Notes |
---|---|---|---|---|
numDerivativesAtStart | [0..1] | xsd:integer | Default value is "0". from type gml:AbstractCurveSegmentType | |
numDerivativesAtEnd | [0..1] | xsd:integer | Default value is "0". from type gml:AbstractCurveSegmentType | |
numDerivativeInterior | [0..1] | xsd:integer | Default value is "0". from type gml:AbstractCurveSegmentType | |
interpolation | [0..1] | gml:CurveInterpolationType | Fixed value is "polynomialSpline". | |
isPolynomial | [0..1] | xsd:boolean | Fixed value is "true". |
Used in
- Type gml:ArrayAssociationType (Element gml:members)
- Type gml:CurveSegmentArrayPropertyType (Element gml:segments)
Substitution hierarchy
- gml:AbstractObject
- can be substituted with gml:AbstractCurveSegment
- can be substituted with gml:BSpline
- can be substituted with gml:Bezier
- can be substituted with gml:BSpline
- can be substituted with gml:AbstractCurveSegment
Sample instance
<gml:Bezier> <gml:pos>1.0 1.0</gml:pos> <gml:degree>1</gml:degree> <gml:knot> <gml:Knot> <gml:value>1.0</gml:value> <gml:multiplicity>1</gml:multiplicity> <gml:weight>1.0</gml:weight> </gml:Knot> </gml:knot> </gml:Bezier>