complexType OffsetCurveType

diagram
namespace	http://www.opengis.net/gml
type	extension of gml:AbstractCurveSegmentType
properties	base  gml:AbstractCurveSegmentType
children	gml:offsetBase gml:distance gml:refDirection
used by	element  OffsetCurve
attributes	Name   Type   Use   Default   Fixed   annotation numDerivativesAtStart xs:integer optional   0      documentation The attribute "numDerivativesAtStart" specifies the type of continuity between this curve segment and its predecessor. If this is the first curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts. A value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity. A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity. NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that allow them to adjust the values of the derivatives to support C 1 or higher continuity. numDerivativesAtEnd xs:integer optional   0      documentation The attribute "numDerivativesAtEnd" specifies the type of continuity between this curve segment and its successor. If this is the last curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts. A value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity. A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity. NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that allow them to adjust the values of the derivatives to support C 1 or higher continuity. numDerivativeInterior xs:integer optional   0      documentation The attribute "numDerivativesInterior" specifies the type of continuity that is guaranteed interior to the curve. The default value of "0" means simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts. A value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity. A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity. NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that allow them to adjust the values of the derivatives to support C 1 or higher continuity.
annotation	documentation An offset curve is a curve at a constant distance from the basis curve. They can be useful as a cheap and simple alternative to constructing curves that are offsets by definition.
source	<xs:complexType name="OffsetCurveType">   <xs:annotation>     <xs:documentation>An offset curve is a curve at a constant distance from the basis curve. They can be useful as a cheap and simple alternative to constructing curves that are offsets by definition.</xs:documentation>   </xs:annotation>   <xs:complexContent>     <xs:extension base="gml:AbstractCurveSegmentType">       <xs:sequence>         <xs:element name="offsetBase" type="gml:CurvePropertyType">           <xs:annotation>             <xs:documentation>offsetBase is a reference to thecurve from which this curve is define as an offset.</xs:documentation>           </xs:annotation>         </xs:element>         <xs:element name="distance" type="gml:LengthType">           <xs:annotation>             <xs:documentation>distance is the distance at which the offset curve is generated from the basis curve. In 2D systems, positive distances are to be to the left of the basis curve, and the negative distances are to be to the right of the basis curve.</xs:documentation>           </xs:annotation>         </xs:element>         <xs:element name="refDirection" type="gml:VectorType" minOccurs="0">           <xs:annotation>             <xs:documentation>refDistance is used to define the vector        direction of the offset curve from the basis curve. It can        be omitted in the 2D case, where the distance can be        positive or negative. In that case, distance defines left        side (positive distance) or right side (negative distance)        with respect to the tangent to the basis curve.        In 3D the basis curve shall have a well defined tangent        direction for every point. The offset curve at any point        in 3D, the basis curve shall have a well-defined tangent        direction for every point. The offset curve at any point        (parameter) on the basis curve c is in the direction        -   -   -         -                      s = v x t  where  v = c.refDirection()         and        -        t = c.tangent()                                                     -        For the offset direction to be well-defined, v shall not        on any point of the curve be in the same, or opposite,        direction as        -        t.        The default value of the refDirection shall be the local        co-ordinate axis vector for elevation, which indicates up for        the curve in a geographic sense.        NOTE! If the refDirection is the positive tangent to the        local elevation axis ("points upward"), then the offset        vector points to the left of the curve when viewed from        above.</xs:documentation>           </xs:annotation>         </xs:element>       </xs:sequence>     </xs:extension>   </xs:complexContent> </xs:complexType>

element OffsetCurveType/offsetBase

diagram
namespace	http://www.opengis.net/gml
type	gml:CurvePropertyType
properties	isRef  0 content  complex
children	gml:_Curve
attributes	Name   Type   Use   Default   Fixed   annotation type       simple   href          role          arcrole          title          show          actuate          remoteSchema optional         documentation Reference to an XML Schema fragment that specifies the content model of the propertys value. This is in conformance with the XML Schema Section 4.14 Referencing Schemas from Elsewhere.
annotation	documentation offsetBase is a reference to thecurve from which this curve is define as an offset.
source	<xs:element name="offsetBase" type="gml:CurvePropertyType">   <xs:annotation>     <xs:documentation>offsetBase is a reference to thecurve from which this curve is define as an offset.</xs:documentation>   </xs:annotation> </xs:element>

element OffsetCurveType/distance

diagram
namespace	http://www.opengis.net/gml
type	gml:LengthType
properties	isRef  0 content  complex
attributes	Name   Type   Use   Default   Fixed   annotation uom xs:anyURI required
annotation	documentation distance is the distance at which the offset curve is generated from the basis curve. In 2D systems, positive distances are to be to the left of the basis curve, and the negative distances are to be to the right of the basis curve.
source	<xs:element name="distance" type="gml:LengthType">   <xs:annotation>     <xs:documentation>distance is the distance at which the offset curve is generated from the basis curve. In 2D systems, positive distances are to be to the left of the basis curve, and the negative distances are to be to the right of the basis curve.</xs:documentation>   </xs:annotation> </xs:element>

element OffsetCurveType/refDirection

diagram
namespace	http://www.opengis.net/gml
type	gml:VectorType
properties	isRef  0 minOcc  0 maxOcc  1 content  complex
attributes	Name   Type   Use   Default   Fixed   annotation srsName xs:anyURI optional         documentation In general this reference points to a CRS instance of gml:CoordinateReferenceSystemType (see coordinateReferenceSystems.xsd). For well known references it is not required that the CRS description exists at the location the URI points to. If no srsName attribute is given, the CRS must be specified as part of the larger context this geometry element is part of, e.g. a geometric element like point, curve, etc. It is expected that this attribute will be specified at the direct position level only in rare cases. srsDimension xs:positiveInteger optional         documentation The "srsDimension" is the length of coordinate sequence (the number of entries in the list). This dimension is specified by the coordinate reference system. When the srsName attribute is omitted, this attribute shall be omitted. axisLabels gml:NCNameList optional         documentation Ordered list of labels for all the axes of this CRS. The gml:axisAbbrev value should be used for these axis labels, after spaces and forbiddden characters are removed. When the srsName attribute is included, this attribute is optional. When the srsName attribute is omitted, this attribute shall also be omitted. uomLabels gml:NCNameList optional         documentation Ordered list of unit of measure (uom) labels for all the axes of this CRS. The value of the string in the gml:catalogSymbol should be used for this uom labels, after spaces and forbiddden characters are removed. When the axisLabels attribute is included, this attribute shall also be included. When the axisLabels attribute is omitted, this attribute shall also be omitted.
annotation	documentation refDistance is used to define the vector        direction of the offset curve from the basis curve. It can        be omitted in the 2D case, where the distance can be        positive or negative. In that case, distance defines left        side (positive distance) or right side (negative distance)        with respect to the tangent to the basis curve.        In 3D the basis curve shall have a well defined tangent        direction for every point. The offset curve at any point        in 3D, the basis curve shall have a well-defined tangent        direction for every point. The offset curve at any point        (parameter) on the basis curve c is in the direction        -   -   -         -                      s = v x t  where  v = c.refDirection()         and        -        t = c.tangent()                                                     -        For the offset direction to be well-defined, v shall not        on any point of the curve be in the same, or opposite,        direction as        -        t.        The default value of the refDirection shall be the local        co-ordinate axis vector for elevation, which indicates up for        the curve in a geographic sense.        NOTE! If the refDirection is the positive tangent to the        local elevation axis ("points upward"), then the offset        vector points to the left of the curve when viewed from        above.
source	<xs:element name="refDirection" type="gml:VectorType" minOccurs="0">   <xs:annotation>     <xs:documentation>refDistance is used to define the vector        direction of the offset curve from the basis curve. It can        be omitted in the 2D case, where the distance can be        positive or negative. In that case, distance defines left        side (positive distance) or right side (negative distance)        with respect to the tangent to the basis curve.        In 3D the basis curve shall have a well defined tangent        direction for every point. The offset curve at any point        in 3D, the basis curve shall have a well-defined tangent        direction for every point. The offset curve at any point        (parameter) on the basis curve c is in the direction        -   -   -         -                      s = v x t  where  v = c.refDirection()         and        -        t = c.tangent()                                                     -        For the offset direction to be well-defined, v shall not        on any point of the curve be in the same, or opposite,        direction as        -        t.        The default value of the refDirection shall be the local        co-ordinate axis vector for elevation, which indicates up for        the curve in a geographic sense.        NOTE! If the refDirection is the positive tangent to the        local elevation axis ("points upward"), then the offset        vector points to the left of the curve when viewed from        above.</xs:documentation>   </xs:annotation> </xs:element>

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