LatticeXvl Elements

X3D LatticeXvl Elements

The X3D LatticeXvl extension consists of a single element: XvlShell. XvlShell is an extended geometry element that encapsulates all the attributes needed to describe a Lattice structure. The following fragment shows a scene conatining an XvlShell element:

<X3D>
    <Scene>
        <Shape>
<XvlShell>
<!-- structure of XvlShell is described here -->
</XvlShell>
</Shape>
    </Scene>
</X3D>

X3D LatticeXvl DTD

The LatticeXvl DTD describes the XvlShell element.

XvlShell Element

<!-- for future: G1T1 level -->

<!ENTITY % XvlG1T1ShellTypes "" >

<!-- Types of XVL Shells -->

<!ENTITY % XvlShell.shellTypes " %XvlG1T1ShellTypes; POLYGON_MESH | LATTICE_MESH " >

<!-- XvlShell geometry node -->

<!ELEMENT XvlShell (

( (%TextureCoordinateNodes;), ((%CoordinateNodes;) | %WildcardNodes;) ) |

( (%CoordinateNodes;), ((%TextureCoordinateNodes;) | %WildcardNodes;)? ) |

( %WildcardNodes;, ((%TextureCoordinateNodes;) | (%CoordinateNodes;) | %WildcardNodes;)?) )?

>

<!ATTLIST XvlShell

shellType ( %XvlShell.shellTypes; ) #IMPLIED

numberOfDivisions %SFInt32; #IMPLIED

vertexRound %MFFloat; #IMPLIED

edgeStartCoordIndex %MFInt32; #IMPLIED

edgeEndCoordIndex %MFInt32; #IMPLIED

edgeRound %MFFloat; #IMPLIED

edgeStartVector %MFVec3f; #IMPLIED

edgeEndVector %MFVec3f; #IMPLIED

faceCoordIndex %MFInt32; #IMPLIED

faceTexCoordIndex %MFInt32; #IMPLIED

faceEmpty %MFBool; #IMPLIED

faceHidden %MFBool; #IMPLIED

nodeTypeHint NMTOKEN #FIXED "IndexedFaceSet"

DEF ID #IMPLIED

USE IDREF #IMPLIED

>

XvlShell Attributes

Attribute	Description	Default Value
shell Type	Type of shell: POLYGON_MESH - Surface set shell that consists of polygons. LATTICE_MESH - Surface set shell that consists of polygons with rounding.	LATTICE_MESH
numberOfDivisions	Number of subdivisions, (tesselation) of each face.	4
vertexRound	Rounding weight – one per vertex.	NULL
edgeStartCoordIndex	Coordinate indexes for edge start vertices – one per edge.	NULL
EdgeEndCoordIndex	Coordinate indexes for edge end vertices – one per edge.	NULL
EdgeRound	Rounding weight – one per edge.	NULL
EdgeStartVector	Tangent vector at start of edge – one per edge.	NULL
EdgeEndVector	Tangent vector at end of edge – one per edge.	NULL
FaceCoordIndex	Coordinate indexes of each face.	NULL
FaceTexCoordIndex	TextureCoordinate indexes of each face.	NULL
FaceEmpty	Empty flags – one per face. Empty faces are “holes” which do not contribute to the computation of the surface. Since they are not part of the surface, they are never rendered.	NULL
FaceHidden	Hidden flags – one per face. Hidden faces may or may not be empty, but they are never rendered.	NULL