assimp/code/AssetLib/X3D/X3DImporter.hpp

/*
Open Asset Import Library (assimp)
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*/
#ifndef INCLUDED_AI_X3D_IMPORTER_H
#define INCLUDED_AI_X3D_IMPORTER_H

#include <assimp/BaseImporter.h>
#include <assimp/XmlParser.h>
#include <assimp/importerdesc.h>
#include <assimp/scene.h>
#include <assimp/types.h>
#include <assimp/DefaultLogger.hpp>
#include <assimp/ProgressHandler.hpp>

#include <list>
#include <string>
#include <vector>

namespace Assimp {

inline void Throw_ArgOutOfRange(const std::string &argument) {
    throw DeadlyImportError("Argument value is out of range for: \"" + argument + "\".");
}

inline void Throw_CloseNotFound(const std::string &node) {
    throw DeadlyImportError("Close tag for node <" + node + "> not found. Seems file is corrupt.");
}

inline void Throw_ConvertFail_Str2ArrF(const std::string &nodeName, const std::string &pAttrValue) {
    throw DeadlyImportError("In <" + nodeName + "> failed to convert attribute value \"" + pAttrValue +
                            "\" from string to array of floats.");
}

inline void Throw_DEF_And_USE(const std::string &nodeName) {
    throw DeadlyImportError("\"DEF\" and \"USE\" can not be defined both in <" + nodeName + ">.");
}

inline void Throw_IncorrectAttr(const std::string &nodeName, const std::string &pAttrName) {
    throw DeadlyImportError("Node <" + nodeName + "> has incorrect attribute \"" + pAttrName + "\".");
}

inline void Throw_IncorrectAttrValue(const std::string &nodeName, const std::string &pAttrName) {
    throw DeadlyImportError("Attribute \"" + pAttrName + "\" in node <" + nodeName + "> has incorrect value.");
}

inline void Throw_MoreThanOnceDefined(const std::string &nodeName, const std::string &pNodeType, const std::string &pDescription) {
    throw DeadlyImportError("\"" + pNodeType + "\" node can be used only once in " + nodeName + ". Description: " + pDescription);
}

inline void Throw_TagCountIncorrect(const std::string &pNode) {
    throw DeadlyImportError("Count of open and close tags for node <" + pNode + "> are not equivalent. Seems file is corrupt.");
}

inline void Throw_USE_NotFound(const std::string &nodeName, const std::string &pAttrValue) {
    throw DeadlyImportError("Not found node with name \"" + pAttrValue + "\" in <" + nodeName + ">.");
}

inline void LogInfo(const std::string &message) {
    DefaultLogger::get()->info(message);
}

/// \class X3DImporter
/// Class that holding scene graph which include: groups, geometry, metadata etc.
///
/// Limitations.
///
/// Pay attention that X3D is format for interactive graphic and simulations for web browsers.
/// So not all features can be imported using Assimp.
///
/// Unsupported nodes:
/// 	CAD geometry component:
///			"CADAssembly", "CADFace", "CADLayer", "CADPart", "IndexedQuadSet", "QuadSet"
///		Core component:
///			"ROUTE", "ExternProtoDeclare", "ProtoDeclare", "ProtoInstance", "ProtoInterface", "WorldInfo"
///		Distributed interactive simulation (DIS) component:
///			"DISEntityManager", "DISEntityTypeMapping", "EspduTransform", "ReceiverPdu", "SignalPdu", "TransmitterPdu"
///		Cube map environmental texturing component:
///			"ComposedCubeMapTexture", "GeneratedCubeMapTexture", "ImageCubeMapTexture"
///		Environmental effects component:
///			"Background", "Fog", "FogCoordinate", "LocalFog", "TextureBackground"
///		Environmental sensor component:
///			"ProximitySensor", "TransformSensor", "VisibilitySensor"
///		Followers component:
///			"ColorChaser", "ColorDamper", "CoordinateChaser", "CoordinateDamper", "OrientationChaser", "OrientationDamper", "PositionChaser",
///			"PositionChaser2D", "PositionDamper", "PositionDamper2D", "ScalarChaser", "ScalarDamper", "TexCoordChaser2D", "TexCoordDamper2D"
///		Geospatial component:
///			"GeoCoordinate", "GeoElevationGrid", "GeoLocation", "GeoLOD", "GeoMetadata", "GeoOrigin", "GeoPositionInterpolator", "GeoProximitySensor",
///			"GeoTouchSensor", "GeoTransform", "GeoViewpoint"
///		Humanoid Animation (H-Anim) component:
///			"HAnimDisplacer", "HAnimHumanoid", "HAnimJoint", "HAnimSegment", "HAnimSite"
///		Interpolation component:
///			"ColorInterpolator", "CoordinateInterpolator", "CoordinateInterpolator2D", "EaseInEaseOut", "NormalInterpolator", "OrientationInterpolator",
///			"PositionInterpolator", "PositionInterpolator2D", "ScalarInterpolator", "SplinePositionInterpolator", "SplinePositionInterpolator2D",
///			"SplineScalarInterpolator", "SquadOrientationInterpolator",
///		Key device sensor component:
///			"KeySensor", "StringSensor"
///		Layering component:
///			"Layer", "LayerSet", "Viewport"
///		Layout component:
///			"Layout", "LayoutGroup", "LayoutLayer", "ScreenFontStyle", "ScreenGroup"
///		Navigation component:
///			"Billboard", "Collision", "LOD", "NavigationInfo", "OrthoViewpoint", "Viewpoint", "ViewpointGroup"
///		Networking component:
///			"EXPORT", "IMPORT", "Anchor", "LoadSensor"
///		NURBS component:
///			"Contour2D", "ContourPolyline2D", "CoordinateDouble", "NurbsCurve", "NurbsCurve2D", "NurbsOrientationInterpolator", "NurbsPatchSurface",
///			"NurbsPositionInterpolator", "NurbsSet", "NurbsSurfaceInterpolator", "NurbsSweptSurface", "NurbsSwungSurface", "NurbsTextureCoordinate",
///			"NurbsTrimmedSurface"
///		Particle systems component:
///			"BoundedPhysicsModel", "ConeEmitter", "ExplosionEmitter", "ForcePhysicsModel", "ParticleSystem", "PointEmitter", "PolylineEmitter",
///			"SurfaceEmitter", "VolumeEmitter", "WindPhysicsModel"
///		Picking component:
///			"LinePickSensor", "PickableGroup", "PointPickSensor", "PrimitivePickSensor", "VolumePickSensor"
///		Pointing device sensor component:
///			"CylinderSensor", "PlaneSensor", "SphereSensor", "TouchSensor"
///		Rendering component:
///			"ClipPlane"
///		Rigid body physics:
///			"BallJoint", "CollidableOffset", "CollidableShape", "CollisionCollection", "CollisionSensor", "CollisionSpace", "Contact", "DoubleAxisHingeJoint",
///			"MotorJoint", "RigidBody", "RigidBodyCollection", "SingleAxisHingeJoint", "SliderJoint", "UniversalJoint"
///		Scripting component:
///			"Script"
///		Programmable shaders component:
///			"ComposedShader", "FloatVertexAttribute", "Matrix3VertexAttribute", "Matrix4VertexAttribute", "PackagedShader", "ProgramShader", "ShaderPart",
///			"ShaderProgram",
///		Shape component:
///			"FillProperties", "LineProperties", "TwoSidedMaterial"
///		Sound component:
///			"AudioClip", "Sound"
///		Text component:
///			"FontStyle", "Text"
///		Texturing3D Component:
///			"ComposedTexture3D", "ImageTexture3D", "PixelTexture3D", "TextureCoordinate3D", "TextureCoordinate4D", "TextureTransformMatrix3D",
///			"TextureTransform3D"
///		Texturing component:
///			"MovieTexture", "MultiTexture", "MultiTextureCoordinate", "MultiTextureTransform", "PixelTexture", "TextureCoordinateGenerator",
///			"TextureProperties",
///		Time component:
///			"TimeSensor"
///		Event Utilities component:
///			"BooleanFilter", "BooleanSequencer", "BooleanToggle", "BooleanTrigger", "IntegerSequencer", "IntegerTrigger", "TimeTrigger",
///		Volume rendering component:
///			"BlendedVolumeStyle", "BoundaryEnhancementVolumeStyle", "CartoonVolumeStyle", "ComposedVolumeStyle", "EdgeEnhancementVolumeStyle",
///			"IsoSurfaceVolumeData", "OpacityMapVolumeStyle", "ProjectionVolumeStyle", "SegmentedVolumeData", "ShadedVolumeStyle",
///			"SilhouetteEnhancementVolumeStyle", "ToneMappedVolumeStyle", "VolumeData"
///
/// Supported nodes:
///		Core component:
///			"MetadataBoolean", "MetadataDouble", "MetadataFloat", "MetadataInteger", "MetadataSet", "MetadataString"
///		Geometry2D component:
///			"Arc2D", "ArcClose2D", "Circle2D", "Disk2D", "Polyline2D", "Polypoint2D", "Rectangle2D", "TriangleSet2D"
///		Geometry3D component:
///			"Box", "Cone", "Cylinder", "ElevationGrid", "Extrusion", "IndexedFaceSet", "Sphere"
///		Grouping component:
///			"Group", "StaticGroup", "Switch", "Transform"
///		Lighting component:
///			"DirectionalLight", "PointLight", "SpotLight"
///		Networking component:
///			"Inline"
///		Rendering component:
///			"Color", "ColorRGBA", "Coordinate", "IndexedLineSet", "IndexedTriangleFanSet", "IndexedTriangleSet", "IndexedTriangleStripSet", "LineSet",
///			"PointSet", "TriangleFanSet", "TriangleSet", "TriangleStripSet", "Normal"
///		Shape component:
///			"Shape", "Appearance", "Material"
///		Texturing component:
///			"ImageTexture", "TextureCoordinate", "TextureTransform"
///
/// Limitations of attribute "USE".
/// If "USE" is set then node must be empty, like that:
///		<Node USE='name'/>
/// not the
///		<Node USE='name'><!-- something --> </Node>
///
/// Ignored attributes: "creaseAngle", "convex", "solid".
///
/// Texture coordinates generating: only for Sphere, Cone, Cylinder. In all other case used PLANE mapping.
///		It's better that Assimp main code has powerful texture coordinates generator. Then is not needed to
///		duplicate this code in every importer.
///
/// Lighting limitations.
///		If light source placed in some group with "DEF" set. And after that some node is use it group with "USE" attribute then
///		you will get error about duplicate light sources. That's happening because Assimp require names for lights but do not like
///		duplicates of it )).
///
///	Color for faces.
/// That's happening when attribute "colorPerVertex" is set to "false". But Assimp do not hold how many colors has mesh and require
/// equal length for mVertices and mColors. You will see the colors but vertices will use call which last used in "colorIdx".
///
///	That's all for now. Enjoy
///
enum class X3DElemType {
    ENET_Group, ///< Element has type "Group".
    ENET_MetaBoolean, ///< Element has type "Metadata boolean".
    ENET_MetaDouble, ///< Element has type "Metadata double".
    ENET_MetaFloat, ///< Element has type "Metadata float".
    ENET_MetaInteger, ///< Element has type "Metadata integer".
    ENET_MetaSet, ///< Element has type "Metadata set".
    ENET_MetaString, ///< Element has type "Metadata string".
    ENET_Arc2D, ///< Element has type "Arc2D".
    ENET_ArcClose2D, ///< Element has type "ArcClose2D".
    ENET_Circle2D, ///< Element has type "Circle2D".
    ENET_Disk2D, ///< Element has type "Disk2D".
    ENET_Polyline2D, ///< Element has type "Polyline2D".
    ENET_Polypoint2D, ///< Element has type "Polypoint2D".
    ENET_Rectangle2D, ///< Element has type "Rectangle2D".
    ENET_TriangleSet2D, ///< Element has type "TriangleSet2D".
    ENET_Box, ///< Element has type "Box".
    ENET_Cone, ///< Element has type "Cone".
    ENET_Cylinder, ///< Element has type "Cylinder".
    ENET_Sphere, ///< Element has type "Sphere".
    ENET_ElevationGrid, ///< Element has type "ElevationGrid".
    ENET_Extrusion, ///< Element has type "Extrusion".
    ENET_Coordinate, ///< Element has type "Coordinate".
    ENET_Normal, ///< Element has type "Normal".
    ENET_TextureCoordinate, ///< Element has type "TextureCoordinate".
    ENET_IndexedFaceSet, ///< Element has type "IndexedFaceSet".
    ENET_IndexedLineSet, ///< Element has type "IndexedLineSet".
    ENET_IndexedTriangleSet, ///< Element has type "IndexedTriangleSet".
    ENET_IndexedTriangleFanSet, ///< Element has type "IndexedTriangleFanSet".
    ENET_IndexedTriangleStripSet, ///< Element has type "IndexedTriangleStripSet".
    ENET_LineSet, ///< Element has type "LineSet".
    ENET_PointSet, ///< Element has type "PointSet".
    ENET_TriangleSet, ///< Element has type "TriangleSet".
    ENET_TriangleFanSet, ///< Element has type "TriangleFanSet".
    ENET_TriangleStripSet, ///< Element has type "TriangleStripSet".
    ENET_Color, ///< Element has type "Color".
    ENET_ColorRGBA, ///< Element has type "ColorRGBA".
    ENET_Shape, ///< Element has type "Shape".
    ENET_Appearance, ///< Element has type "Appearance".
    ENET_Material, ///< Element has type "Material".
    ENET_ImageTexture, ///< Element has type "ImageTexture".
    ENET_TextureTransform, ///< Element has type "TextureTransform".
    ENET_DirectionalLight, ///< Element has type "DirectionalLight".
    ENET_PointLight, ///< Element has type "PointLight".
    ENET_SpotLight, ///< Element has type "SpotLight".

    ENET_Invalid ///< Element has invalid type and possible contain invalid data.
};

struct X3DNodeElementBase {
    X3DNodeElementBase *Parent;
    std::string ID;
    std::list<X3DNodeElementBase *> Children;
    X3DElemType Type;

protected:
    X3DNodeElementBase(X3DElemType type, X3DNodeElementBase *pParent) :
            Type(type), Parent(pParent) {
        // empty
    }
};

/// This struct hold <Color> value.
struct CX3DImporter_NodeElement_Color : X3DNodeElementBase {
    std::list<aiColor3D> Value; ///< Stored value.

    /// Constructor
    /// \param [in] pParent - pointer to parent node.
    CX3DImporter_NodeElement_Color(X3DNodeElementBase *pParent) :
            X3DNodeElementBase(X3DElemType::ENET_Color, pParent) {}

}; // struct CX3DImporter_NodeElement_Color

/// This struct hold <ColorRGBA> value.
struct CX3DImporter_NodeElement_ColorRGBA : X3DNodeElementBase {
    std::list<aiColor4D> Value; ///< Stored value.

    /// Constructor
    /// \param [in] pParent - pointer to parent node.
    CX3DImporter_NodeElement_ColorRGBA(X3DNodeElementBase *pParent) :
            X3DNodeElementBase(X3DElemType::ENET_ColorRGBA, pParent) {}

}; // struct CX3DImporter_NodeElement_ColorRGBA

/// This struct hold <Coordinate> value.
struct CX3DImporter_NodeElement_Coordinate : public X3DNodeElementBase {
    std::list<aiVector3D> Value; ///< Stored value.

    /// Constructor
    /// \param [in] pParent - pointer to parent node.
    CX3DImporter_NodeElement_Coordinate(X3DNodeElementBase *pParent) :
            X3DNodeElementBase(X3DElemType::ENET_Coordinate, pParent) {}

}; // struct CX3DImporter_NodeElement_Coordinate

/// This struct hold <Normal> value.
struct CX3DImporter_NodeElement_Normal : X3DNodeElementBase {
    std::list<aiVector3D> Value; ///< Stored value.

    /// Constructor
    /// \param [in] pParent - pointer to parent node.
    CX3DImporter_NodeElement_Normal(X3DNodeElementBase *pParent) :
            X3DNodeElementBase(X3DElemType::ENET_Normal, pParent) {}

}; // struct CX3DImporter_NodeElement_Normal

/// This struct hold <TextureCoordinate> value.
struct CX3DImporter_NodeElement_TextureCoordinate : X3DNodeElementBase {
    std::list<aiVector2D> Value; ///< Stored value.

    /// Constructor
    /// \param [in] pParent - pointer to parent node.
    CX3DImporter_NodeElement_TextureCoordinate(X3DNodeElementBase *pParent) :
            X3DNodeElementBase(X3DElemType::ENET_TextureCoordinate, pParent) {}

}; // struct CX3DImporter_NodeElement_TextureCoordinate

/// Two-dimensional figure.
struct CX3DImporter_NodeElement_Geometry2D : X3DNodeElementBase {
    std::list<aiVector3D> Vertices; ///< Vertices list.
    size_t NumIndices; ///< Number of indices in one face.
    bool Solid; ///< Flag: if true then render must use back-face culling, else render must draw both sides of object.

    /// Constructor.
    /// \param [in] pParent - pointer to parent node.
    /// \param [in] pType - type of geometry object.
    CX3DImporter_NodeElement_Geometry2D(X3DElemType pType, X3DNodeElementBase *pParent) :
            X3DNodeElementBase(pType, pParent), Solid(true) {}

}; // class CX3DImporter_NodeElement_Geometry2D

/// Three-dimensional body.
struct CX3DImporter_NodeElement_Geometry3D : X3DNodeElementBase {
    std::list<aiVector3D> Vertices; ///< Vertices list.
    size_t NumIndices; ///< Number of indices in one face.
    bool Solid; ///< Flag: if true then render must use back-face culling, else render must draw both sides of object.

    /// Constructor.
    /// \param [in] pParent - pointer to parent node.
    /// \param [in] pType - type of geometry object.
    CX3DImporter_NodeElement_Geometry3D(X3DElemType pType, X3DNodeElementBase *pParent) :
            X3DNodeElementBase(pType, pParent), Vertices(), NumIndices(0), Solid(true) {
        // empty
    }
}; // class CX3DImporter_NodeElement_Geometry3D

/// Uniform rectangular grid of varying height.
struct CX3DImporter_NodeElement_ElevationGrid : CX3DImporter_NodeElement_Geometry3D {
    bool NormalPerVertex; ///< If true then normals are defined for every vertex, else for every face(line).
    bool ColorPerVertex; ///< If true then colors are defined for every vertex, else for every face(line).
    /// If the angle between the geometric normals of two adjacent faces is less than the crease angle, normals shall be calculated so that the faces are
    /// shaded smoothly across the edge; otherwise, normals shall be calculated so that a lighting discontinuity across the edge is produced.
    float CreaseAngle;
    std::vector<int32_t> CoordIdx; ///< Coordinates list by faces. In X3D format: "-1" - delimiter for faces.

    /// Constructor.
    /// \param [in] pParent - pointer to parent node.
    /// \param [in] pType - type of geometry object.
    CX3DImporter_NodeElement_ElevationGrid(X3DElemType pType, X3DNodeElementBase *pParent) :
            CX3DImporter_NodeElement_Geometry3D(pType, pParent) {}
}; // class CX3DImporter_NodeElement_IndexedSet

/// Shape with indexed vertices.
struct CX3DImporter_NodeElement_IndexedSet : public CX3DImporter_NodeElement_Geometry3D {
    /// The ccw field defines the ordering of the vertex coordinates of the geometry with respect to user-given or automatically generated normal vectors
    /// used in the lighting model equations. If ccw is TRUE, the normals shall follow the right hand rule; the orientation of each normal with respect to
    /// the vertices (taken in order) shall be such that the vertices appear to be oriented in a counterclockwise order when the vertices are viewed (in the
    /// local coordinate system of the Shape) from the opposite direction as the normal. If ccw is FALSE, the normals shall be oriented in the opposite
    /// direction. If normals are not generated but are supplied using a Normal node, and the orientation of the normals does not match the setting of the
    /// ccw field, results are undefined.
    bool CCW;
    std::vector<int32_t> ColorIndex; ///< Field to specify the polygonal faces by indexing into the <Color> or <ColorRGBA>.
    bool ColorPerVertex; ///< If true then colors are defined for every vertex, else for every face(line).
    /// The convex field indicates whether all polygons in the shape are convex (TRUE). A polygon is convex if it is planar, does not intersect itself,
    /// and all of the interior angles at its vertices are less than 180 degrees. Non planar and self intersecting polygons may produce undefined results
    /// even if the convex field is FALSE.
    bool Convex;
    std::vector<int32_t> CoordIndex; ///< Field to specify the polygonal faces by indexing into the <Coordinate>.
    /// If the angle between the geometric normals of two adjacent faces is less than the crease angle, normals shall be calculated so that the faces are
    /// shaded smoothly across the edge; otherwise, normals shall be calculated so that a lighting discontinuity across the edge is produced.
    float CreaseAngle;
    std::vector<int32_t> NormalIndex; ///< Field to specify the polygonal faces by indexing into the <Normal>.
    bool NormalPerVertex; ///< If true then normals are defined for every vertex, else for every face(line).
    std::vector<int32_t> TexCoordIndex; ///< Field to specify the polygonal faces by indexing into the <TextureCoordinate>.

    /// Constructor.
    /// \param [in] pParent - pointer to parent node.
    /// \param [in] pType - type of geometry object.
    CX3DImporter_NodeElement_IndexedSet(X3DElemType pType, X3DNodeElementBase *pParent) :
            CX3DImporter_NodeElement_Geometry3D(pType, pParent) {}
}; // class CX3DImporter_NodeElement_IndexedSet

/// Shape with set of vertices.
struct CX3DImporter_NodeElement_Set : CX3DImporter_NodeElement_Geometry3D {
    /// The ccw field defines the ordering of the vertex coordinates of the geometry with respect to user-given or automatically generated normal vectors
    /// used in the lighting model equations. If ccw is TRUE, the normals shall follow the right hand rule; the orientation of each normal with respect to
    /// the vertices (taken in order) shall be such that the vertices appear to be oriented in a counterclockwise order when the vertices are viewed (in the
    /// local coordinate system of the Shape) from the opposite direction as the normal. If ccw is FALSE, the normals shall be oriented in the opposite
    /// direction. If normals are not generated but are supplied using a Normal node, and the orientation of the normals does not match the setting of the
    /// ccw field, results are undefined.
    bool CCW;
    bool ColorPerVertex; ///< If true then colors are defined for every vertex, else for every face(line).
    bool NormalPerVertex; ///< If true then normals are defined for every vertex, else for every face(line).
    std::vector<int32_t> CoordIndex; ///< Field to specify the polygonal faces by indexing into the <Coordinate>.
    std::vector<int32_t> NormalIndex; ///< Field to specify the polygonal faces by indexing into the <Normal>.
    std::vector<int32_t> TexCoordIndex; ///< Field to specify the polygonal faces by indexing into the <TextureCoordinate>.
    std::vector<int32_t> VertexCount; ///< Field describes how many vertices are to be used in each polyline(polygon) from the <Coordinate> field.

    /// Constructor.
    /// \param [in] pParent - pointer to parent node.
    /// \param [in] pType - type of geometry object.
    CX3DImporter_NodeElement_Set(X3DElemType type, X3DNodeElementBase *pParent) :
            CX3DImporter_NodeElement_Geometry3D(type, pParent) {}

}; // class CX3DImporter_NodeElement_Set

/// This struct hold <Shape> value.
struct CX3DImporter_NodeElement_Shape : X3DNodeElementBase {

    /// Constructor
    /// \param [in] pParent - pointer to parent node.
    CX3DImporter_NodeElement_Shape(X3DNodeElementBase *pParent) :
            X3DNodeElementBase(X3DElemType::ENET_Shape, pParent) {}
}; // struct CX3DImporter_NodeElement_Shape

/// This struct hold <Appearance> value.
struct CX3DImporter_NodeElement_Appearance : public X3DNodeElementBase {

    /// Constructor
    /// \param [in] pParent - pointer to parent node.
    CX3DImporter_NodeElement_Appearance(X3DNodeElementBase *pParent) :
            X3DNodeElementBase(X3DElemType::ENET_Appearance, pParent) {}

}; // struct CX3DImporter_NodeElement_Appearance

struct CX3DImporter_NodeElement_Material : public X3DNodeElementBase {
    float AmbientIntensity; ///< Specifies how much ambient light from light sources this surface shall reflect.
    aiColor3D DiffuseColor; ///< Reflects all X3D light sources depending on the angle of the surface with respect to the light source.
    aiColor3D EmissiveColor; ///< Models "glowing" objects. This can be useful for displaying pre-lit models.
    float Shininess; ///< Lower shininess values produce soft glows, while higher values result in sharper, smaller highlights.
    aiColor3D SpecularColor; ///< The specularColor and shininess fields determine the specular highlights.
    float Transparency; ///< Specifies how "clear" an object is, with 1.0 being completely transparent, and 0.0 completely opaque.

    /// Constructor.
    /// \param [in] pParent - pointer to parent node.
    /// \param [in] pType - type of geometry object.
    CX3DImporter_NodeElement_Material(X3DNodeElementBase *pParent) :
            X3DNodeElementBase(X3DElemType::ENET_Material, pParent),
            AmbientIntensity(0.0f),
            DiffuseColor(),
            EmissiveColor(),
            Shininess(0.0f),
            SpecularColor(),
            Transparency(1.0f) {
        // empty
    }
}; // class CX3DImporter_NodeElement_Material

/// This struct hold <ImageTexture> value.
struct CX3DImporter_NodeElement_ImageTexture : X3DNodeElementBase {
    /// RepeatS and RepeatT, that specify how the texture wraps in the S and T directions. If repeatS is TRUE (the default), the texture map is repeated
    /// outside the [0.0, 1.0] texture coordinate range in the S direction so that it fills the shape. If repeatS is FALSE, the texture coordinates are
    /// clamped in the S direction to lie within the [0.0, 1.0] range. The repeatT field is analogous to the repeatS field.
    bool RepeatS;
    bool RepeatT; ///< See \ref RepeatS.
    std::string URL; ///< URL of the texture.

                     /// Constructor
    /// \param [in] pParent - pointer to parent node.
    CX3DImporter_NodeElement_ImageTexture(X3DNodeElementBase *pParent) :
            X3DNodeElementBase(X3DElemType::ENET_ImageTexture, pParent) {}

}; // struct CX3DImporter_NodeElement_ImageTexture

/// This struct hold <TextureTransform> value.
struct CX3DImporter_NodeElement_TextureTransform : X3DNodeElementBase {
    aiVector2D Center; ///< Specifies a translation offset in texture coordinate space about which the rotation and scale fields are applied.
    float Rotation; ///< Specifies a rotation in angle base units of the texture coordinates about the center point after the scale has been applied.
    aiVector2D Scale; ///< Specifies a scaling factor in S and T of the texture coordinates about the center point.
    aiVector2D Translation; ///<  Specifies a translation of the texture coordinates.

    /// Constructor
    /// \param [in] pParent - pointer to parent node.
    CX3DImporter_NodeElement_TextureTransform(X3DNodeElementBase *pParent) :
            X3DNodeElementBase(X3DElemType::ENET_TextureTransform, pParent) {}

}; // struct CX3DImporter_NodeElement_TextureTransform

struct CX3DNodeElementGroup : X3DNodeElementBase {
    aiMatrix4x4 Transformation; ///< Transformation matrix.

    /// As you know node elements can use already defined node elements when attribute "USE" is defined.
    /// Standard search when looking for an element in the whole scene graph, existing at this moment.
    /// If a node is marked as static, the children(or lower) can not search for elements in the nodes upper then static.
    bool Static;

    bool UseChoice; ///< Flag: if true then use number from \ref Choice to choose what the child will be kept.
    int32_t Choice; ///< Number of the child which will be kept.

    /// Constructor.
    /// \param [in] pParent - pointer to parent node.
    /// \param [in] pStatic - static node flag.
    CX3DNodeElementGroup(X3DNodeElementBase *pParent, const bool pStatic = false) :
            X3DNodeElementBase(X3DElemType::ENET_Group, pParent), Static(pStatic), UseChoice(false) {}
};

struct X3DNodeElementMeta : X3DNodeElementBase {
    std::string Name; ///< Name of metadata object.
    std::string Reference;

    virtual ~X3DNodeElementMeta() {
        // empty
    }

protected:
    X3DNodeElementMeta(X3DElemType type, X3DNodeElementBase *parent) :
            X3DNodeElementBase(type, parent) {
        // empty
    }
};

struct X3DNodeElementMetaBoolean : X3DNodeElementMeta {
    std::vector<bool> Value; ///< Stored value.

    explicit X3DNodeElementMetaBoolean(X3DNodeElementBase *pParent) :
            X3DNodeElementMeta(X3DElemType::ENET_MetaBoolean, pParent) {
        // empty
    }
};

struct X3DNodeElementMetaDouble : X3DNodeElementMeta {
    std::vector<double> Value; ///< Stored value.

    explicit X3DNodeElementMetaDouble(X3DNodeElementBase *pParent) :
            X3DNodeElementMeta(X3DElemType::ENET_MetaDouble, pParent) {
        // empty
    }
};

struct X3DNodeElementMetaFloat : public X3DNodeElementMeta {
    std::vector<float> Value; ///< Stored value.

    explicit X3DNodeElementMetaFloat(X3DNodeElementBase *pParent) :
            X3DNodeElementMeta(X3DElemType::ENET_MetaFloat, pParent) {
        // empty
    }
};

struct X3DNodeElementMetaInt : public X3DNodeElementMeta {
    std::vector<int32_t> Value; ///< Stored value.

    explicit X3DNodeElementMetaInt(X3DNodeElementBase *pParent) :
            X3DNodeElementMeta(X3DElemType::ENET_MetaInteger, pParent) {
        // empty
    }
};

struct X3DNodeElementMetaSet : public X3DNodeElementMeta {
    std::list<X3DNodeElementMeta> Value; ///< Stored value.

    explicit X3DNodeElementMetaSet(X3DNodeElementBase *pParent) :
            X3DNodeElementMeta(X3DElemType::ENET_MetaSet, pParent) {
        // empty
    }
};

struct X3DNodeElementMetaString : X3DNodeElementMeta {
    std::list<std::string> Value; ///< Stored value.

    explicit X3DNodeElementMetaString(X3DNodeElementBase *pParent) :
            X3DNodeElementMeta(X3DElemType::ENET_MetaString, pParent) {
        // empty
    }
};

/// \struct CX3DImporter_NodeElement_Light
/// This struct hold <TextureTransform> value.
struct X3DNodeNodeElementLight : X3DNodeElementBase {
    float AmbientIntensity; ///< Specifies the intensity of the ambient emission from the light.
    aiColor3D Color; ///< specifies the spectral colour properties of both the direct and ambient light emission as an RGB value.
    aiVector3D Direction; ///< Specifies the direction vector of the illumination emanating from the light source in the local coordinate system.
    /// \var Global
    /// Field that determines whether the light is global or scoped. Global lights illuminate all objects that fall within their volume of lighting influence.
    /// Scoped lights only illuminate objects that are in the same transformation hierarchy as the light.
    bool Global;
    float Intensity; ///< Specifies the brightness of the direct emission from the light.
    /// \var Attenuation
    /// PointLight node's illumination falls off with distance as specified by three attenuation coefficients. The attenuation factor
    /// is: "1 / max(attenuation[0] + attenuation[1] * r + attenuation[2] * r2, 1)", where r is the distance from the light to the surface being illuminated.
    aiVector3D Attenuation;
    aiVector3D Location; ///< Specifies a translation offset of the centre point of the light source from the light's local coordinate system origin.
    float Radius; ///< Specifies the radial extent of the solid angle and the maximum distance from location that may be illuminated by the light source.
    float BeamWidth; ///< Specifies an inner solid angle in which the light source emits light at uniform full intensity.
    float CutOffAngle; ///< The light source's emission intensity drops off from the inner solid angle (beamWidth) to the outer solid angle (cutOffAngle).

    /// Constructor
    /// \param [in] pParent - pointer to parent node.
    /// \param [in] pLightType - type of the light source.
    X3DNodeNodeElementLight(X3DElemType pLightType, X3DNodeElementBase *pParent) :
            X3DNodeElementBase(pLightType, pParent) {}

}; // struct CX3DImporter_NodeElement_Light

using X3DElementList = std::list<X3DNodeElementBase*>;

class X3DImporter : public BaseImporter {
public:
    std::list<X3DNodeElementBase *> NodeElement_List; ///< All elements of scene graph.

public:
    /// Default constructor.
    X3DImporter();

    /// Default destructor.
    ~X3DImporter();

    /***********************************************/
    /******** Functions: parse set, public *********/
    /***********************************************/

    /// Parse X3D file and fill scene graph. The function has no return value. Result can be found by analyzing the generated graph.
    /// Also exception can be thrown if trouble will found.
    /// \param [in] pFile - name of file to be parsed.
    /// \param [in] pIOHandler - pointer to IO helper object.
    void ParseFile(const std::string &pFile, IOSystem *pIOHandler);
    bool CanRead(const std::string &pFile, IOSystem *pIOHandler, bool pCheckSig) const;
    void InternReadFile(const std::string &pFile, aiScene *pScene, IOSystem *pIOHandler);
    const aiImporterDesc *GetInfo() const;
    void Clear();
    void readMetadata(XmlNode &node);
    void readScene(XmlNode &node);
    void readViewpoint(XmlNode &node);
    void readMetadataObject(XmlNode &node);
    void ParseDirectionalLight(XmlNode &node);
    void Postprocess_BuildNode(const X3DNodeElementBase &pNodeElement, aiNode &pSceneNode, std::list<aiMesh *> &pSceneMeshList,
            std::list<aiMaterial *> &pSceneMaterialList, std::list<aiLight *> &pSceneLightList) const;

private:
    static const aiImporterDesc Description;
    X3DNodeElementBase *mNodeElementCur;
    aiScene *mScene;
}; // class X3DImporter

} // namespace Assimp

#endif // INCLUDED_AI_X3D_IMPORTER_H