X3DLayerNode

<xs:complexType name="X3DLayerNode" abstract="true">
  <xs:annotation>
    <xs:appinfo>
      <xs:element name="viewport" type="SFNode" fixed="inputOutputField" default="X3DViewportNode"/>
      <xs:attribute name="componentName" type="xs:NMTOKEN" fixed="Layering"/>
      <xs:attribute name="componentLevel" type="xs:positiveInteger" fixed="1"/>
    </xs:appinfo>
    <xs:documentation source="http://www.web3d.org/documents/specifications/19775-1/V3.3/Part01/components/layering.html#X3DLayerNode"/>
  </xs:annotation>
  <xs:complexContent>
    <xs:extension base="X3DNode">
      <xs:attribute name="isPickable" type="SFBool" default="true"/>
    </xs:extension>
    <!-- Viewport node handled as part of nodes implementing this interface, since including it here leads to a nondeterministic content model. -->
  </xs:complexContent>
</xs:complexType>