StelOBJ Class Reference

Representation of a custom subset of a Wavefront .obj file, including only triangle data and materials.

#include <StelOBJ.hpp>

Data Structures
struct	Material
	Defines a material loaded from an .mtl file. More...
struct	MaterialGroup
	Represents a bunch of faces following after each other that use the same material. More...
struct	Object
	Represents an OBJ object as defined with the 'o' statement. More...
struct	Vertex
	A Vertex struct holds the vertex itself (position), corresponding texture coordinates, normals, tangents and bitangents It does not use Vec3f etc. More...

Public Types
enum	VertexOrder {   XYZ, XZY, YXZ, YZX,   ZXY, ZYX }
	Possible vertex orderings with load()
typedef QVector< MaterialGroup >	MaterialGroupList
typedef QVector< Vec3f >	V3Vec
typedef QVector< Vec2f >	V2Vec
typedef QVector< Vertex >	VertexList
typedef QVector< unsigned int >	IndexList
typedef QVector< unsigned short >	ShortIndexList
typedef QVector< Material >	MaterialList
typedef QMap< QString, int >	MaterialMap
typedef QVector< Object >	ObjectList
typedef QMap< QString, int >	ObjectMap

Public Member Functions
	StelOBJ ()
	Constructs an empty StelOBJ. Use load() to load data from a .obj file.
void	clear ()
	Resets all data contained in this StelOBJ.
unsigned int	getFaceCount () const
	Returns the number of faces. More...
const VertexList &	getVertexList () const
	Returns an vertex list, suitable for loading into OpenGL arrays.
const IndexList &	getIndexList () const
	Returns an index list, suitable for use with OpenGL element arrays.
const MaterialList &	getMaterialList () const
	Returns the list of materials.
const ObjectList &	getObjectList () const
	Returns the list of objects.
const ObjectMap &	getObjectMap () const
	Returns the object map (mapping the object names to their indices in the object list)
const AABBox &	getAABBox () const
	Returns the global AABB of all vertices of the OBJ.
const Vec3f &	getCentroid () const
	Returns the global centroid of all vertices of the OBJ. More...
bool	load (const QString &filename, const VertexOrder vertexOrder=VertexOrder::XYZ)
	Loads an .obj file by name. More...
bool	load (QIODevice &device, const QString &basePath, const VertexOrder vertexOrder=VertexOrder::XYZ)
	Loads an .obj file from the specified device. More...
bool	isLoaded () const
	Returns true if this object contains valid data from a load() method.
void	rebuildNormals ()
	Rebuilds vertex normals as the average of face normals.
bool	canUseShortIndices () const
	Returns if unsigned short indices can be used instead of unsigned int indices, to save some memory. More...
ShortIndexList	getShortIndexList () const
	Converts the index list (as returned by getIndexList()) to use unsigned short instead of integer. More...
void	scale (double factor)
	Scales the vertex positions according to the given factor. More...
void	transform (const QMatrix4x4 &mat, bool onlyPosition=false)
	Applies the given transformation matrix to the vertex data. More...
void	splitVertexData (V3Vec *position, V2Vec *texCoord=Q_NULLPTR, V3Vec *normal=Q_NULLPTR, V3Vec *tangent=Q_NULLPTR, V3Vec *bitangent=Q_NULLPTR) const
	Splits the vertex data into separate arrays. More...
void	clearVertexData ()
	Clears the internal vertex list to save space, meaning getVertexList() returns an empty list! The other members are unaffected (indices, materials, objects etc. More...

Member Function Documentation

canUseShortIndices()

bool StelOBJ::canUseShortIndices ( ) const

inline

This can only be done if the model has less vertices than std::numeric_limits<unsigned short>::max()

clearVertexData()

void StelOBJ::clearVertexData

(

)

still work). The vertex list can only be restored when the OBJ data is freshly loaded again, so don't do this if you require it later.

This is intended to be used together with splitVertexData(), when you want your own vertex format.

getCentroid()

const Vec3f& StelOBJ::getCentroid ( ) const

inline

Note

This is a very simple centroid calculation which simply accumulates all vertex positions and divides by their number. Most notably, it does not take vertex density into account, so this may not correspond to the geometric center/center of mass of the object

getFaceCount()

unsigned int StelOBJ::getFaceCount ( ) const

inline

We only use triangle faces, so this is always the index count divided by 3.

getShortIndexList()

ShortIndexList StelOBJ::getShortIndexList

(

)

const

If this is not possible (canUseShortIndices() returns false), an empty list is returned.

load() [1/2]

bool StelOBJ::load	(	const QString &	filename,
		const VertexOrder	vertexOrder = VertexOrder::XYZ
	)

Supports .gz decompression, and then calls load(QIODevice) for the actual loading.

Returns

true if load was successful

load() [2/2]

bool StelOBJ::load	(	QIODevice &	device,
		const QString &	basePath,
		const VertexOrder	vertexOrder = VertexOrder::XYZ
	)

Parameters

device	The device to load OBJ data from
basePath	The path to use to find additional files (like material definitions)
vertexOrder	The order to use for vertex positions

Returns

true if load was successful

scale()

void StelOBJ::scale

(

double

factor

)

This may be useful for importing, because many exporters don't handle very large or very small models well. For example, the solar system objects are modeled with kilometer units, and then converted to AU on loading.

splitVertexData()

void StelOBJ::splitVertexData	(	V3Vec *	position,
		V2Vec *	texCoord = Q_NULLPTR,
		V3Vec *	normal = Q_NULLPTR,
		V3Vec *	tangent = Q_NULLPTR,
		V3Vec *	bitangent = Q_NULLPTR
	)		const

If a given parameter vector is null, it is not filled.

transform()

void StelOBJ::transform	(	const QMatrix4x4 &	mat,
		bool	onlyPosition = false
	)

Parameters

onlyPosition

If true, only the position information is transformed, the normals/tangents are skipped